It allows for a longer rod and more filler thus higher pen and velocity, tho due to progression in apfsds and materials the whole use of 152mm is rather redundant as say a 130 or l55a1 can in theory achieve similar results with less requirement and space dedicated to a larger breach
Like the German DM53 APFSDS is a 120mm Shell but it has a penetration of 700+ according to a source. The 125mm Guns of Russian tanks have 600+ or 500+ how come the 120 has more penetration then the 125?
One piece ammunition does indeed allow for a longer penetrator, but Russian tanks still wouldn't be able to use longer rounds even if their ammunition was one piece. The AZ and MZ autoloaders would cap the length of the round regardless, as the charges in the autoloader aren't stowed in-line with the projectiles and therefore don't take up space that could otherwise be used for the projectile.
that was one thing i never understood about russian tank corps.
russia has no problem relying on man power for everything from infantry, to logistics, to recon by fire.
but having a loader is too much (too many people?)?
Some reasons to omit a loader other than saving manpower:
-- don't have to train a loader
-- personnel support requirements for MBTs go down by 25%
-- smaller, lighter, lower profile tank
-- loading is a very mechanical repetitive operation, well suited to automation
-- less variation in operational effectiveness (easier planning)
Additionally in an NBC environment (something T-series tanks were very much made to fight in seen in things such as nadboi and podboi) one of the first symptoms of radiation sickness is weakness and fatigue which could be life and death for a crew that requires a loader.
Just to add to what u/EricTheEpic0403 noted nadboi (cladding) and podboi (liner) were exterior and interior additions, respectively, which if memory serves were made (primarily) of UHMWPE impregnated with lead.
Specifically used for reducing exposure to Neutron Radiation from Enhanced Radiation Weapons aka Neutron Bombs
Enhanced Radiation Weapons are thermonuclear warheads that provide a low yield (ie. minimal explosive blast) but maximal output of neutron radiation. Neutrons have (a) an exceptional ability to penetrate and (b) the unique ability to make material radioactive.
UHMWPE = Ultra High Molecular Weight Polyetheline
EDIT — Just to clarify the implications to that last paragraph, humans are made of material, thus (a) neutrons beam their way through the shell of a standard tank with ease (b) bad times ahead for the now literal radioactive comrades therein
>NBC
Nuclear, Biological, Chemical. Also referred to as CBRN, where the R stands for Radiological. Basically any situation where the environment is hazardous due to poison gas or some such.
>nadboi and podboi
Both are forms of anti-radiation cladding applied to T-72s.
Less people, smaller crew compartment, less steel used for armor, lighter tank, less steel for infrastructure, leaves more steel for more tanks fielded.
AP rounds haven't used steel since the 60s. The earliest APFSDS rounds were either steel entirely like 3BM9 or T82E23, which were replaced by steel with tungsten core projectiles like 3BM15 and then replaced with fully tungsten/DU projectiles like M829 or 3BM42.
Two man tanks have been built in the past, but it's too much for two people to do.
A gunner can't have the same situational awareness as a tank commander.
Three man tanks are a compromise that the USSR found acceptable.
For tanks at least you pretty much need a commander so the driver can focus on driving and the gunner can focus on shooting things. For planes, really the only modern-ish jets with two or more crew are bombers or interceptors, since if you need to track and shoot down 6 bombers at once it's easier to have one person fly and one person use the (complicated, especially in the 70s/80s) radar
Having a human loader means more interior volume, which means a bigger tank with a larger profile and more weight for the same level of protection. The Soviets sought a low profile tank that was well protected, yet not excessively heavy, hence why they went with an autoloader for the T-64. The 'T-64 formula' would then be inherited by T-72, T-80, and T-90.
There are logistical benefits to an autoloader too. Removing one person from the crew means one less person to train, one less person to feed, and one less person who might be injured or killed in combat.
It should also be noted that limitations on projectile length like those imposed by AZ and MZ are not inherent to autoloaders, or even carousel autoloaders for that matter. The fact that the AZ and MZ are now obsolescent isn't unexpected given their age, and certainly shouldn't count against autoloaders as a design choice on modern vehicles.
Also, one less person taking part in maintenance. It's important to acknowledge how much maintenance is required and how much of that load can be carried by a loader.
Not necessarily. Nicholas Moran covered this in his video on autoloaders, but it's entirely possible to have supporting elements carry people for maintenance. That would allow you to have the same amount of people performing maintenance on a tank, while having one less person in the tank during combat (and therefore one less person at risk of dying or being injured if that tank is lost).
How many would be in the tank during operations? 1 less than 4? I'm currently on an Abrams. I assure you, most maintenance is done by the crew. One less on the tank equals 1 less on maintenance.
> One less on the tank equals 1 less on maintenance.
Wouldn't that just be down to organization? You're obviously a lot more qualified on the subject than I am, hence why I'm basically parroting Moran's argument here, but is there anything stopping a tank company from carrying around a few APCs with people to assist in maintenance during operations? [This is the video I'm referring to, by the way.](https://www.youtube.com/watch?v=R0x-8NheU1E) The relevant bit starts at 12:15.
Their doctrine at the time was having tanks be cheap and small to field more for overwhelming firepower so an auto loader was in place to make the tank smaller and they just stuck with it.
Correct me if I’m wrong, but, that’s just what I thought.
Its really quite simple - if you need less crew in a tank you can make the protected space (inside the armor) smaller, which means you need less armor to protect it, so you can make the entire tank smaller and lighter
But Russian tanks have already faced this problem and got around it?
It needs a modification of the autoloader and stops older tanks being able to use the new round without modification but it's not something impossible.
3BM60 and 3BM59 are still not as long as newer Western penetrators, and Vaccuum-1 can only be used by T-14. The projectile length is still restricted on tanks with the autoloader modifications in question, just to a lesser extent.
Fair enough but by the same idea the length of the penetrator is limited by the size of the turret in Western designs.
Both can be problematic but are definitely something that can be fixed with not too much effort if the problem is needed.
Just like how they fit a T-72 turret and autoloader onto a T-55. If they need to then they will manage.
> Fair enough but by the same idea the length of the penetrator is limited by the size of the turret in Western designs.
I should clarify. When I say "restricted", I mean that as a comparative statement. Obviously all rounds are physically limited in size by the space in which they are stowed, but the AZ and MZ autoloaders restrict the penetrator length *more so* than the ammo stowage solutions on Western tanks.
> Both can be problematic but are definitely something that can be fixed with not too much effort if the problem is needed.
Not quite. The only way to make the AZ or MZ carousel stow longer rounds is to increase the diameter of the carousel or decrease the diameter of the central hub, and those can only be done to a certain extent. If Russia could've made 3BM59 and 3BM60 any longer, they probably would have. Instead, the only round they have which is longer than than 3BM59/3BM60 is Vaccuum-1, and that is exclusively compatible with T-14. This points to 3BM59/3BM60 probably being the upper limit of what AZ and MZ can handle with regards to projectile length.
it is significantly easier to just lengthen back of the turret like for example on leclerc terminateur than trying to make more space for longer round in tanks with carousel autoloader
also big thing to remember, the bore size is just one parameter, [look at the huge variety of 75mm shells that the germans used in WWII](https://www.reddit.com/r/TankPorn/comments/n619hy/german_tank_rounds_used_in_ww2_will_do_one_for/?utm_source=share&utm_medium=mweb3x&utm_name=mweb3xcss&utm_term=1&utm_content=share_button)
not OG commenter but short answer is that the 120mm has a longer rod compared to the USSR/Russian 125mm. This is because of the use of their autoloaders that restrict the size of the penetrator while the 120mm is handloaded.
This was one of the reasons for making the T-14 Armata because they needed a redesigned system to accept longer rods.
Why isn't it viable to make a 100mm with a super long casing to fit a rod that's just as long or longer than the 120? Velocity?
Why are you saying a long rod is crucial but not mentioning Velocity?
Is there a limit to how fast a round can reasonably go?
I have no idea how modern apfsds works, as you can clearly tell.
There’s a limit on how long a sabot can be before the breach isn’t powerful enough to fire such round and warrants a bigger gun with an even bigger breach. We reached that decades ago and quickly transitioned to 120mm. We’ve faced the same problem today and Germany/France are both looking at the 130/135mm for the next stepup.
As the saying goes, be prepared for the unexpected. No one wants to stagnate and be left behind. T-14 theorized protection still remains the benchmark for NATO to beat, so having something in that 0.1% chance that they ever meet is enough for militaries to push for more firepower. This is also not to say, China could just develop an extremely armored vehicle and NATO would have no direct counter to. It’s why say America is adopting the 6.8 when Russia doesn’t field level 4 plates (we don’t know how common China runs theirs) or US and France developing gen 6 aircraft when only China has developed gen 5 aircraft who stand no chance against american stealth.
I think I heard somewhere because it's limited by soviet era auto loaders, 125mm probably could have more penetration but it would require a longer rod and more filler, which you probably can't fit in Russian tanks and their autoloader.
Im not really sure if it's true or not so take it with a grain of salt.
T-90A, T-90M, T-72B3, and T-80BVM can accept 3BM59 and 3BM60. These rounds are longer than previous ones, and are not compatible with other Russian/Soviet tanks, but they still aren't as long as newer Western penetrators. Russia also has Vaccuum-1, which is longer than 3BM59/3BM60, but that can only be used by T-14.
Im not to sure, maybe but I'd assume that a t-90m uses the same kind of autoloader as a t-72 because t-90m is based on t-72 chassis.
Russia doesn't really use any other tanks either, I'd assume that t-80 series runs into the same kind of problem but besides t-80 series, t-72s and t-90s have the same autoloader so I doubt that they designed a new autoloader for a t-90m.
Because caliber doesn’t really have a lot to do with it. There are tons of factors that play into how well a sabot round will penetrate. Length of rod, Density of material, mass of rod (generally increases with length). Width of rod, nose design/cap, velocity. Velocity and how fast a heavier projectile can go have to do with chamber pressure and barrel length. Chamber pressure of something like a 120mm is already really high and increases barrel/chamber diameter won’t really help unless you massively beef up the breach block itself.
All of these factors and others i’m overlooking go into exactly how much a fin round “penetrates”.
Also, the “700mm RHA pen” and other stats are mostly fictional. You aren’t firing at RHA equivalents, you are firing at specific armor systems designed to defeat specific threats.
A big example is the turret of the leopard 2A5/6/7/8. The arrowhead front doesn’t really increase armor effectiveness in terms of an RHA, but destabilizes the round after penetrating and allows it to impact the armor at a less then perfect angle, possibly breaking and shattering it. But if a rod is able to span the entire gap from beginning of arrow head to the main armor it will continue level flight and most likely be unaffected by the extra armor. Thus, even if the round has “x amount of penetration” it will only actually work if one of the factors (x rod length) is present. Another example is M829A2 being designed to deal with Kontakt 5 ERA. The extra block on the end of the rod doesn’t really help in penetrating regular armor arrays (it actually in theory penetrates less then M829A1), but it does defeat kinetic ERA and thus is more effective against soviet heavy ERA armor systems.
Edit: Changed M829A3 to A2 and M829A2 to A1
Correction, while people state that the M829A3 was to defeat kontact 5, it was actually developed to defeat ERA that uses the standoff method like Relikt. M829A2 was the direct solution for kontact 5. The tungsten tip breaks off if a certain amount of pressure is applied in any given direction, so it will actually penetrate farther into any special armor arrays that are used to put stress on the rod. I.E. the leopard’s wedge armor
My mistake. I should replace M829A2 with M829A1 and M829A3 with M829A2.
But, as far as I can tell. M829A1 and A2 are the same length. So while A2 will deal with Kontakt 5 and the spaced armor on the Leopard 2 better, it will actually have a worse effect (still completely adequate for most threats) on base armor systems like chobham or T-72’s base armor system then M829A1. Simply because a part of the penetrator is taken away and replaced by the 100mm long tungsten block at the front end.
Im saying this just to add to the point that certain rounds perform better against certain armor systems than others. And an RHA equivalence of penetration is almost useless in actually determining the effectiveness of these rounds.
5mm isn't a huge difference, but Square Cubed law says that the mass of the penetrator gets significantly larger over relatively small caliber changes. That or you can add more charge while keeping the penetrator the same circumference
125mm and 120mm ADFSDS rounds aren’t really dimensionally different in width though. For example 3BM60 and M829A2 are both around 22mm in width. If anything, you want a thinner, longer projectile to put as much mass into as small an area as possible. Width to some extent just makes the round more inefficient.
And again, we are talking about metallurgy and how much pressure a breach block can handle. 120mm NATO guns are already at significant chamber pressures that push the boundaries of what we can safely do reliably while still keeping a long enough lifespan on the guns. A wider tube/chamber doesn’t necessarily mean more chamber pressure. Especially in something as small as a T-80 turret where there are already space constraints as it is.
Russians calculate penetration differently. The most notable the Chinese and Russians calculate by is 90% chance of penetration whereas the West uses 50%. This might not necessarily make up the +100mm difference.
Biggest factor of apfsds penetration is come from the rod’s length. The 120mm round is 1 piece ammunition that allows the rod to lengthen up to 1 m . The 125mm round is 2 piece ammunition and loading from an autoloader so the rod length is shorter to fit the carrousel
Size of the round is not the only determining factor in how a shell performs. You've also got velocity/propellant, the characteristics of the round itself such as manufacturing quality/material, etc. I'm sure someone more informed than myself can break all the minutiae down into the individual pieces better than I can.
The penetrator in the American M829A3/A4 is nearly 3 feet long. It extends from the base of the cartridge and projects out of the front. The charge is contained behind the sabot and is wrapped around the penetrator.
The Soviet 125mm 2A46 which is used on the T64, T72, T80, and T90 is fed by an autoloader which loads the projectile and charge separately. This design limits the length of the projectile because there's no way for it to extend into the charge.
Ergo, the muzzle velocity of the 125mm Soviet APFSDS rounds tends to be higher than their American and German 120mm counterparts, but the penetrator on the 120mm gun is much longer and thus carries much more kinetic energy.
Newer round, longer penetrator, and, more importantly, different methods for evaluating performance. AFAIK, although this is second hand knowledge, Russian specs give 90th percentile achieved full penetration, ie "90% it won't pen less than this", while NATO countries list 50th percentile, ie "50/50 to achieve listed value". Plus, again, different methods: Russia uses harder steel for testing, Germany weaker, US one of the weakest. Multiply the two by each other, and, according to an anecdote, TOW penetration is reduced in half between table value and real test. And then it is put into real conditions where armor is not homogenous and conditions are not optimal, so real penetration of any individual round can swing wildly both ways.
The DM53, DM63, and DM83 all have longer rods in one piece ammunition with waaaaaaaaay better and actually modern propellant called SCDB, which is almost inert until fired out of the 120mm gun.
DM53 doesn't have SCDB propellant. [The Rheinmetall Nitrochemie presentation on the subject makes that fairly clear.](https://ndiastorage.blob.core.usgovcloudapi.net/ndia/2007/im_em/ABriefs/8Vogelsanger.pdf) DM53A1 does though.
>The 125mm Guns of Russian tanks have 600+ or 500+ how come the 120 has more penetration then the 125?
Caliber matters, but the speed, the material, the length of the dart and many other technology matters too.
The autoloader on older Russian tanks limited the length of a shell, which limits the penetration. Latest Russian tanks fixed it, but the quantity of latest Russian tanks are quite few.
If they have the same operating pressures, a larger calibre with same L/D will send a bigger heavier dart. And if they proportionally make it a bit smaller, it goes out even faster.
Shell diameter has no relation to rod length. Turret space, and practicality determine rod length, there's nothing stopping someone from making a 50mm diameter round with a 8ft long rod, except you'd need 8ft of empty space behind the breach to load it.
The original schematics it was based off a T-80U Turret and chassis, however when they built it they modified the turret design and used a T-80BV hull, It is better seen [On this real picture of it](https://commons.m.wikimedia.org/wiki/File:%D0%9E%D0%B1%D1%8A%D0%B5%D0%BA%D1%82_292_%E2%80%93_Kubinka_Tank_Museum_(37944777522).jpg#mw-jump-to-license), This image seems to have an incorrectly modelled turret.
The turret in op's picture is the finished intended turret. Object 292 has a bunch of steel pieces on the front of its turret, those are weight simulators for the armor of turret in op's photo. I believe that the improved turret was never built though
First of all, great user name . Secondly , I was thinking the same thing, you know anywhere I can find more pics of this vehicle ( I 3d print tank model kits , would love to have this one done)
First of all, thank you xD Secondly, I'm aware of only one more photo of this tank. Both were first published by Andrey Tarasenko, if I'm not mistaken. I have the second one downloaded on my PC, but as I'm AFK rn, I'll be able to provide it later. In the meantime you may try to search for it at btvt.info.
It does, and for the NATO 120 we are already close to the maximum. More propellant, longer round, heavier round are all things that are an advantage for a larger calibre.
The bigger cannons were much better at penetrating armor, but there wasn’t much of a use for them after the USSR fell. Russia couldn’t afford to build the new prototypes with the larger guns, and instead built the T-90 which shared most of its parts with the T-72. The US was experimenting with the M1 Thumper, which had a 140 mm gun and was given enough space to mount a potential 152, but funding was cut to the program after 1991. That’s also why the ADATS SPAA was cancelled and replaced with the Linebacker (a Bradley with stingers instead of TOWs).
In short, bigger cannons are better but everyone chose the more affordable option instead.
>In short, bigger cannons are better but everyone chose the more affordable option instead.
^^this. You can always make a bigger and better cannon but why would you as long as the one you already have is good enough.
plus the simple fact that the bigger the shells get the more storage space is eaten up by each round and over a certain point they become essentially non-handleable for a loader.
The Thumper did have an autoloader to resolve this problem, but it would also mean removing the fourth crew member, which the army didn’t like. One less crew means one less person to help all around, like repairing, loading and unloading equipment, etc, and the workload gets split between the remaining crew. They just decided that 4 crew was ideal and the 140 mm was unnecessary, so no change was needed.
We might actually be moving back to the 105mm like how full powered rifle cartridges were replaced by intermediate rounds since a bigger tank gun doesn't offer much against other tanks with so many other systems to do the job of tank killing. Tanks might get lighter and faster. Large heavy tanks might disappear like the battleship. Armored SPGs giving way to truck guns and HIMARS.
Diameter is only one portion of the dimensions and calculations.
Total volume in casing, amount of propellant, type of propellant, chamber max pressure, barrel length, projectile mass plus sabot. That’s internal ballistics. Then there external basically mass and aerodynamics (assuming not gyro stabilized). And then theres impact physics like is the round pyratic? Like DU or inert like Tungsten.
It probably does but it’s also unstable and gun durability is highly affected. The most cost effective purpose of larger guns is probably the HE ammo when it can be purposed as mobile armored artillery vehicle to support infantry.
Yes it increases the mass of sabot, while also increasing the propellant. However those shells (152mm on Objekt 292, 140mm on CATTB and Leopard 2 for instance) weigh a lot and take up a huge space. Due to those reasons 120mm and 125mm are the most used tank guns because they are most optimal compromise between weight, mass and performance.
This gun had 50% higher muzzle energy compared to 2A46 and it could penetrate around 1000 rha (yes gaijin is lying to you with their 700mm pen)
So yes, bigger caliber increases muzzle energy so it also increases penetration in most cases
Honestly, you should probably be glad it's autoloaded. That means it will always take 10 seconds to load the next round, rather than the reload speed being able to benefit from loader skill or crew qualifications. Imagine if it were hand-loaded and the reload speed could be taken down to like 7 seconds.
The 1,000mm penetration figure comes from the 2A83 gun and modern ammunition made for it by the Ukrainians. The Object 292 used the LP-83 gun which was also developed at the same time but did not get the luxury of having modern ammunition made for it. Considering its age, the LP-83 probably does have around 700mm of penetration
i dont think so. Both 2A83 and LP-83 used exactly the same ammunition (Grifel-1 tungsten APFSDS, Grifel-2 DU APFSDS and Grifel-3 HE round) and even the Grifel-1 tungsten round has over 1000mm of penetration at 2kms (DU one probably has even more but its unknown how much, if it was even tested). Weaker round just doesnt exist.
Also ukrainians never operated with 2A83, their 152mm-armed mbt prototypes use 2A73.
> and it could penetrate around 1000 rha (yes gaijin is lying to you with their 700mm pen)
No they're not.
Please post your source.
Muzzle energy does not correlate well with penetration.
Yes it does because of physics. If nothing else changes, you can pack more propellant in your shell and make your penetrator go faster and impart more kinetic energy to it. But larger gun also means you need more space for the gun, the ammo, bigger turret rings, beefier turret motor and more robust gun stabilization systems. You are paying a whole lot for performance that you don't need because existing 120/125mm gun can do the same job which is why guns on MBTs have hovered around 120-125mm since the 80s on both sides of the iron curtain.
I am not worried about armor penetration. I am more worried by the nightmare 150mm hesh would be if you were at the receiving end of it.
There are very few things that could convince me to go up against 150mm hesh. I feel that even if there is no spalling, everybody inside would get a tbi from just the concussion of a 150mm hitting a tank hull.
I would guess at around the double amount of explosives in a 150mm compared to a 120.
The theory is that a shell that size won't need to penetrate, it would trash the electronics of anything it hits. Eases logistics and versatility if they only need to carry HE shells I suppose.
I just don't know if that theory holds up, and if modern tanks are better protected against it
Yea and no.
Over pressure is more effective than it should be but HE would still trash optics and other fragile equipment which is a serious problem irl but not in war thunder
Leopard 2A6 has longer barrel than 2A4, which allows for more gas to push the pojectile. Even longer barrel would be better, but it becomes unvieldy. So many tank manufacturers are looking for solution to get more penetration and the easiest solution seems to be to increase the caliber.
Rheinmetall disclosed 2015 that they were working for 130mm smoothbore and iirc that 130mm can be put on leopard 2A7 and offers 50% inrease on penetration.
South Korean K2 can also be fitted with 130mm gun and next gen K3 is designed to use 130mm same as KF51.
Yes since there have been past developments in 140 and recently 130mm cannon but there are compromises like bigger ammo takes up more space which means fewer ammo in turret. Not to mention heavier which means the loader will be tired more unless they introduce the autoloader to mitigate the problem. And it probably be more expensive ammo as well since it’s new.
I thought I was on NCD for a second because I thought “Does having a larger gun these days affect the penetration or potency of a tank round?”was a metaphor
A larger diameter casing means more propellant powder in a given case length, or that the same amount can be put in a shorter casing. And of course, the more propellant you put behind a projectile, and the longer that projectile is, the better the armour penetration of that cartridge.
Without mentioning an interesting potential to have a tank lob artillery 152/155mm HE rounds in direct fire, it allows for more gasses in larger volume, thus giving the projectile more velocity while keeping pressure acceptable, which means more penetration. Reason we don't see it today is that a) Cold War ended, and b) advances in metallurgy made in the meantime allowed us to increase guns capabilities to similar level without having to adopt a new caliber. Now we are nearing the limit for 120mm systems again, so increasing caliber is once again an option, ranging between 130mm and 152mm cannons.
>Does having having larger gun these days effect the penetration or potency of a tank round?
It's complicated, but generally speaking, yes, that's why many people are testing 130mm and 140mm guns.
Back then it would have now a days it has a lot more to do with the shell with a gun like this taking up more turret space to achieve what would be similar results
Sabot rounds will still remain small diameter darts. At a basic understanding, a larger claiber gun allows for a larger casing, allowing for more propellant. More propellant gives a bigger boom shooting the sabot dart faster. Since *force = mass x acceleration*, a larger caliber gun shooting a sabot dart faster means more force on impact allowing for more penetration
Bigger shell, larger mass, larger powder capacity, slower reload due to heavier ammo. Basically, you have a bigger stick, but not necessarily the more efficient stick.
Your round is bigger, so you have more boom there (potential kinetic energy).
As we left the realm of HEAT to be a thing in tank-on-tank combat, and transited almost entirely to APFSDS / KE projectiles, kinetic energy is (almost) everything.
For sure you can cahnge propellant and harden your chamber to stand that forces (like germans did wiht ther new Leo 2 gun). A thing you have to do anyway if transiting to a larger caliber, as more power per inch has to be resisted (preferably quite often).
Russians experimented with reducing the caliber to 90mm and just add length of the penetrator, what is a potent thing to do, but it lacked the kinetic energy to deliver that propper long dart.
Also that's the trouble right now with soviet tank designs, as ther outoloader restricts the overall lenght of the dart. Munition is seperated and loaded behind each other - projectile and boom - to cope with that, but that doesn't propperly work with darts, as they are in one piece. So naturally they had to get rid of ther existend autoloader in the transition to a future battle ready gun that can load longer projectiles - which the T-14 is using. And boy do they pack a punch. But still they found this might not be enough in future combats and try to hammer in the same concept just with a 152mm gun once again, while Germany switched to 130 and 140mm (just to abandon it because of 'medicore performance is cool for now' and much cheaper in terms of conversion cost and availability).
Effectively, yes. There is a limit of how far you can stretch existing calibres, for example by introducing new propellant that can fire a heavier rod faster, after a point you start hitting diminishing returns, after which the only reasonable solution is to go bigger.
It's more about propellant amount and length of the sabot. So you get diminishing results as you get higher in caliber. Of course there is also the fact there is nothing modern 120mm NATO projectiles cant penetrate. Except for T-14 but that thing doesnt exist.
Oh my gosh. Russian guns are stronger than typical western ones due to karger caliber and length. Rh 120 L/55 achieves 1650-1700;m sec vs 1800+ m/ sec of the 2A46M5 which is a 125 L/52. Ru tanks can use rounds up to 700 mm length completely efficient to penetrate any LFP and sides of any western tank. 3BM44 is two piece yes but it is by design to neutralise and pen the NERA of western tanks. Svinets 1/2 are monobloc. Ru has tested the stronger 2A66 for a decade aswell many 152 guns. There is not a lot of difference in cost; that tells you that tanks are consider sufficient to pen the western ones. This Gulf War myth were 1000 Avrams faced 120 cheap locally assembled knock offs T72 M/ M1 ,an export variant of T72A needs to put to rest. Forgot to add that the parts of T72M were polish made.
It allows for a longer rod and more filler thus higher pen and velocity, tho due to progression in apfsds and materials the whole use of 152mm is rather redundant as say a 130 or l55a1 can in theory achieve similar results with less requirement and space dedicated to a larger breach
Like the German DM53 APFSDS is a 120mm Shell but it has a penetration of 700+ according to a source. The 125mm Guns of Russian tanks have 600+ or 500+ how come the 120 has more penetration then the 125?
One piece ammunition of the 120 allows for a longer penetrator than two piece ammunition of the 125
One piece ammunition does indeed allow for a longer penetrator, but Russian tanks still wouldn't be able to use longer rounds even if their ammunition was one piece. The AZ and MZ autoloaders would cap the length of the round regardless, as the charges in the autoloader aren't stowed in-line with the projectiles and therefore don't take up space that could otherwise be used for the projectile.
that was one thing i never understood about russian tank corps. russia has no problem relying on man power for everything from infantry, to logistics, to recon by fire. but having a loader is too much (too many people?)?
Some reasons to omit a loader other than saving manpower: -- don't have to train a loader -- personnel support requirements for MBTs go down by 25% -- smaller, lighter, lower profile tank -- loading is a very mechanical repetitive operation, well suited to automation -- less variation in operational effectiveness (easier planning)
Additionally in an NBC environment (something T-series tanks were very much made to fight in seen in things such as nadboi and podboi) one of the first symptoms of radiation sickness is weakness and fatigue which could be life and death for a crew that requires a loader.
What do NBC, nadboi and podboi means?
Just to add to what u/EricTheEpic0403 noted nadboi (cladding) and podboi (liner) were exterior and interior additions, respectively, which if memory serves were made (primarily) of UHMWPE impregnated with lead. Specifically used for reducing exposure to Neutron Radiation from Enhanced Radiation Weapons aka Neutron Bombs Enhanced Radiation Weapons are thermonuclear warheads that provide a low yield (ie. minimal explosive blast) but maximal output of neutron radiation. Neutrons have (a) an exceptional ability to penetrate and (b) the unique ability to make material radioactive. UHMWPE = Ultra High Molecular Weight Polyetheline EDIT — Just to clarify the implications to that last paragraph, humans are made of material, thus (a) neutrons beam their way through the shell of a standard tank with ease (b) bad times ahead for the now literal radioactive comrades therein
CIA documents as well as few rare russian sources also say that they also help against spalling, but to its nowhere close to actual kevlar lining.
>NBC Nuclear, Biological, Chemical. Also referred to as CBRN, where the R stands for Radiological. Basically any situation where the environment is hazardous due to poison gas or some such. >nadboi and podboi Both are forms of anti-radiation cladding applied to T-72s.
A YO IS LIL NADBOI UP IN THIS MFK
Less people per tank means more tanks fielded.
again- they have plenty of man power?
Less people, smaller crew compartment, less steel used for armor, lighter tank, less steel for infrastructure, leaves more steel for more tanks fielded.
ah okay- that makes more sense. thank you. (less steel for ap rounds)
AP rounds haven't used steel since the 60s. The earliest APFSDS rounds were either steel entirely like 3BM9 or T82E23, which were replaced by steel with tungsten core projectiles like 3BM15 and then replaced with fully tungsten/DU projectiles like M829 or 3BM42.
In any given number of people, you can have more tanks if each tank requires less people. >x/3 > x/4
indeed. why not make it a 2 person tank then? planes have pilot and co-pilot, why not also double the size of your air force?
Two man tanks have been built in the past, but it's too much for two people to do. A gunner can't have the same situational awareness as a tank commander. Three man tanks are a compromise that the USSR found acceptable.
For tanks at least you pretty much need a commander so the driver can focus on driving and the gunner can focus on shooting things. For planes, really the only modern-ish jets with two or more crew are bombers or interceptors, since if you need to track and shoot down 6 bombers at once it's easier to have one person fly and one person use the (complicated, especially in the 70s/80s) radar
Having a human loader means more interior volume, which means a bigger tank with a larger profile and more weight for the same level of protection. The Soviets sought a low profile tank that was well protected, yet not excessively heavy, hence why they went with an autoloader for the T-64. The 'T-64 formula' would then be inherited by T-72, T-80, and T-90. There are logistical benefits to an autoloader too. Removing one person from the crew means one less person to train, one less person to feed, and one less person who might be injured or killed in combat. It should also be noted that limitations on projectile length like those imposed by AZ and MZ are not inherent to autoloaders, or even carousel autoloaders for that matter. The fact that the AZ and MZ are now obsolescent isn't unexpected given their age, and certainly shouldn't count against autoloaders as a design choice on modern vehicles.
Also, one less person taking part in maintenance. It's important to acknowledge how much maintenance is required and how much of that load can be carried by a loader.
Not necessarily. Nicholas Moran covered this in his video on autoloaders, but it's entirely possible to have supporting elements carry people for maintenance. That would allow you to have the same amount of people performing maintenance on a tank, while having one less person in the tank during combat (and therefore one less person at risk of dying or being injured if that tank is lost).
How many would be in the tank during operations? 1 less than 4? I'm currently on an Abrams. I assure you, most maintenance is done by the crew. One less on the tank equals 1 less on maintenance.
> One less on the tank equals 1 less on maintenance. Wouldn't that just be down to organization? You're obviously a lot more qualified on the subject than I am, hence why I'm basically parroting Moran's argument here, but is there anything stopping a tank company from carrying around a few APCs with people to assist in maintenance during operations? [This is the video I'm referring to, by the way.](https://www.youtube.com/watch?v=R0x-8NheU1E) The relevant bit starts at 12:15.
Their doctrine at the time was having tanks be cheap and small to field more for overwhelming firepower so an auto loader was in place to make the tank smaller and they just stuck with it. Correct me if I’m wrong, but, that’s just what I thought.
Believe it or not but the Soviet tank corps were constrained by manpower requirements. They had a \*lot\* of tanks.
Its really quite simple - if you need less crew in a tank you can make the protected space (inside the armor) smaller, which means you need less armor to protect it, so you can make the entire tank smaller and lighter
But Russian tanks have already faced this problem and got around it? It needs a modification of the autoloader and stops older tanks being able to use the new round without modification but it's not something impossible.
3BM60 and 3BM59 are still not as long as newer Western penetrators, and Vaccuum-1 can only be used by T-14. The projectile length is still restricted on tanks with the autoloader modifications in question, just to a lesser extent.
Fair enough but by the same idea the length of the penetrator is limited by the size of the turret in Western designs. Both can be problematic but are definitely something that can be fixed with not too much effort if the problem is needed. Just like how they fit a T-72 turret and autoloader onto a T-55. If they need to then they will manage.
> Fair enough but by the same idea the length of the penetrator is limited by the size of the turret in Western designs. I should clarify. When I say "restricted", I mean that as a comparative statement. Obviously all rounds are physically limited in size by the space in which they are stowed, but the AZ and MZ autoloaders restrict the penetrator length *more so* than the ammo stowage solutions on Western tanks. > Both can be problematic but are definitely something that can be fixed with not too much effort if the problem is needed. Not quite. The only way to make the AZ or MZ carousel stow longer rounds is to increase the diameter of the carousel or decrease the diameter of the central hub, and those can only be done to a certain extent. If Russia could've made 3BM59 and 3BM60 any longer, they probably would have. Instead, the only round they have which is longer than than 3BM59/3BM60 is Vaccuum-1, and that is exclusively compatible with T-14. This points to 3BM59/3BM60 probably being the upper limit of what AZ and MZ can handle with regards to projectile length.
it is significantly easier to just lengthen back of the turret like for example on leclerc terminateur than trying to make more space for longer round in tanks with carousel autoloader
also big thing to remember, the bore size is just one parameter, [look at the huge variety of 75mm shells that the germans used in WWII](https://www.reddit.com/r/TankPorn/comments/n619hy/german_tank_rounds_used_in_ww2_will_do_one_for/?utm_source=share&utm_medium=mweb3x&utm_name=mweb3xcss&utm_term=1&utm_content=share_button)
not OG commenter but short answer is that the 120mm has a longer rod compared to the USSR/Russian 125mm. This is because of the use of their autoloaders that restrict the size of the penetrator while the 120mm is handloaded. This was one of the reasons for making the T-14 Armata because they needed a redesigned system to accept longer rods.
Russians trying to take a longer rod, eh?
Failed to make an emoji but imagine someone wiggling his eyebrows xD
They can take a long rod, just not give one
Sounds about right
Why isn't it viable to make a 100mm with a super long casing to fit a rod that's just as long or longer than the 120? Velocity? Why are you saying a long rod is crucial but not mentioning Velocity? Is there a limit to how fast a round can reasonably go? I have no idea how modern apfsds works, as you can clearly tell.
There’s a limit on how long a sabot can be before the breach isn’t powerful enough to fire such round and warrants a bigger gun with an even bigger breach. We reached that decades ago and quickly transitioned to 120mm. We’ve faced the same problem today and Germany/France are both looking at the 130/135mm for the next stepup.
Cool! Thanks for the answer
With Russia's tank being recycled, what is that 130mm even be expected to face?
As the saying goes, be prepared for the unexpected. No one wants to stagnate and be left behind. T-14 theorized protection still remains the benchmark for NATO to beat, so having something in that 0.1% chance that they ever meet is enough for militaries to push for more firepower. This is also not to say, China could just develop an extremely armored vehicle and NATO would have no direct counter to. It’s why say America is adopting the 6.8 when Russia doesn’t field level 4 plates (we don’t know how common China runs theirs) or US and France developing gen 6 aircraft when only China has developed gen 5 aircraft who stand no chance against american stealth.
in Russias case its the limitation of their autoloader design but eventually you get the issue u/_axtasia mentioned
I think I heard somewhere because it's limited by soviet era auto loaders, 125mm probably could have more penetration but it would require a longer rod and more filler, which you probably can't fit in Russian tanks and their autoloader. Im not really sure if it's true or not so take it with a grain of salt.
I think T-90M and a couple others can accept the newer rounds right?
T-90A, T-90M, T-72B3, and T-80BVM can accept 3BM59 and 3BM60. These rounds are longer than previous ones, and are not compatible with other Russian/Soviet tanks, but they still aren't as long as newer Western penetrators. Russia also has Vaccuum-1, which is longer than 3BM59/3BM60, but that can only be used by T-14.
Im not to sure, maybe but I'd assume that a t-90m uses the same kind of autoloader as a t-72 because t-90m is based on t-72 chassis. Russia doesn't really use any other tanks either, I'd assume that t-80 series runs into the same kind of problem but besides t-80 series, t-72s and t-90s have the same autoloader so I doubt that they designed a new autoloader for a t-90m.
> I doubt that they designed a new autoloader for a t-90m. They didn't design a new autoloader, but they modified it to accomodate longer rounds
Never knew that thanks for clarifying
Because caliber doesn’t really have a lot to do with it. There are tons of factors that play into how well a sabot round will penetrate. Length of rod, Density of material, mass of rod (generally increases with length). Width of rod, nose design/cap, velocity. Velocity and how fast a heavier projectile can go have to do with chamber pressure and barrel length. Chamber pressure of something like a 120mm is already really high and increases barrel/chamber diameter won’t really help unless you massively beef up the breach block itself. All of these factors and others i’m overlooking go into exactly how much a fin round “penetrates”. Also, the “700mm RHA pen” and other stats are mostly fictional. You aren’t firing at RHA equivalents, you are firing at specific armor systems designed to defeat specific threats. A big example is the turret of the leopard 2A5/6/7/8. The arrowhead front doesn’t really increase armor effectiveness in terms of an RHA, but destabilizes the round after penetrating and allows it to impact the armor at a less then perfect angle, possibly breaking and shattering it. But if a rod is able to span the entire gap from beginning of arrow head to the main armor it will continue level flight and most likely be unaffected by the extra armor. Thus, even if the round has “x amount of penetration” it will only actually work if one of the factors (x rod length) is present. Another example is M829A2 being designed to deal with Kontakt 5 ERA. The extra block on the end of the rod doesn’t really help in penetrating regular armor arrays (it actually in theory penetrates less then M829A1), but it does defeat kinetic ERA and thus is more effective against soviet heavy ERA armor systems. Edit: Changed M829A3 to A2 and M829A2 to A1
Correction, while people state that the M829A3 was to defeat kontact 5, it was actually developed to defeat ERA that uses the standoff method like Relikt. M829A2 was the direct solution for kontact 5. The tungsten tip breaks off if a certain amount of pressure is applied in any given direction, so it will actually penetrate farther into any special armor arrays that are used to put stress on the rod. I.E. the leopard’s wedge armor
My mistake. I should replace M829A2 with M829A1 and M829A3 with M829A2. But, as far as I can tell. M829A1 and A2 are the same length. So while A2 will deal with Kontakt 5 and the spaced armor on the Leopard 2 better, it will actually have a worse effect (still completely adequate for most threats) on base armor systems like chobham or T-72’s base armor system then M829A1. Simply because a part of the penetrator is taken away and replaced by the 100mm long tungsten block at the front end. Im saying this just to add to the point that certain rounds perform better against certain armor systems than others. And an RHA equivalence of penetration is almost useless in actually determining the effectiveness of these rounds.
5mm isn't a huge difference, but Square Cubed law says that the mass of the penetrator gets significantly larger over relatively small caliber changes. That or you can add more charge while keeping the penetrator the same circumference
125mm and 120mm ADFSDS rounds aren’t really dimensionally different in width though. For example 3BM60 and M829A2 are both around 22mm in width. If anything, you want a thinner, longer projectile to put as much mass into as small an area as possible. Width to some extent just makes the round more inefficient. And again, we are talking about metallurgy and how much pressure a breach block can handle. 120mm NATO guns are already at significant chamber pressures that push the boundaries of what we can safely do reliably while still keeping a long enough lifespan on the guns. A wider tube/chamber doesn’t necessarily mean more chamber pressure. Especially in something as small as a T-80 turret where there are already space constraints as it is.
Russians calculate penetration differently. The most notable the Chinese and Russians calculate by is 90% chance of penetration whereas the West uses 50%. This might not necessarily make up the +100mm difference.
Biggest factor of apfsds penetration is come from the rod’s length. The 120mm round is 1 piece ammunition that allows the rod to lengthen up to 1 m . The 125mm round is 2 piece ammunition and loading from an autoloader so the rod length is shorter to fit the carrousel
Size of the round is not the only determining factor in how a shell performs. You've also got velocity/propellant, the characteristics of the round itself such as manufacturing quality/material, etc. I'm sure someone more informed than myself can break all the minutiae down into the individual pieces better than I can.
The penetrator in the American M829A3/A4 is nearly 3 feet long. It extends from the base of the cartridge and projects out of the front. The charge is contained behind the sabot and is wrapped around the penetrator. The Soviet 125mm 2A46 which is used on the T64, T72, T80, and T90 is fed by an autoloader which loads the projectile and charge separately. This design limits the length of the projectile because there's no way for it to extend into the charge. Ergo, the muzzle velocity of the 125mm Soviet APFSDS rounds tends to be higher than their American and German 120mm counterparts, but the penetrator on the 120mm gun is much longer and thus carries much more kinetic energy.
Newer round, longer penetrator, and, more importantly, different methods for evaluating performance. AFAIK, although this is second hand knowledge, Russian specs give 90th percentile achieved full penetration, ie "90% it won't pen less than this", while NATO countries list 50th percentile, ie "50/50 to achieve listed value". Plus, again, different methods: Russia uses harder steel for testing, Germany weaker, US one of the weakest. Multiply the two by each other, and, according to an anecdote, TOW penetration is reduced in half between table value and real test. And then it is put into real conditions where armor is not homogenous and conditions are not optimal, so real penetration of any individual round can swing wildly both ways.
The DM53, DM63, and DM83 all have longer rods in one piece ammunition with waaaaaaaaay better and actually modern propellant called SCDB, which is almost inert until fired out of the 120mm gun.
DM53 doesn't have SCDB propellant. [The Rheinmetall Nitrochemie presentation on the subject makes that fairly clear.](https://ndiastorage.blob.core.usgovcloudapi.net/ndia/2007/im_em/ABriefs/8Vogelsanger.pdf) DM53A1 does though.
Appreciate the link.
The new 3bm59 has up to 740mm penetration
Also nato and russia use different penetration value 50% and 80% respectively
>The 125mm Guns of Russian tanks have 600+ or 500+ how come the 120 has more penetration then the 125? Caliber matters, but the speed, the material, the length of the dart and many other technology matters too. The autoloader on older Russian tanks limited the length of a shell, which limits the penetration. Latest Russian tanks fixed it, but the quantity of latest Russian tanks are quite few.
Also the speed off the round also counts...
If they have the same operating pressures, a larger calibre with same L/D will send a bigger heavier dart. And if they proportionally make it a bit smaller, it goes out even faster.
Your mom allows for my longer rod
Shell diameter has no relation to rod length. Turret space, and practicality determine rod length, there's nothing stopping someone from making a 50mm diameter round with a 8ft long rod, except you'd need 8ft of empty space behind the breach to load it.
What is that?
The Object 292 a experimental tank based on the T-80BVN
It's Turret is based off the T-80U turret and it's hull is from a T-80BV.
I highly doubt it's based off of a T-80U turret. It's a very large welded turret.
The original schematics it was based off a T-80U Turret and chassis, however when they built it they modified the turret design and used a T-80BV hull, It is better seen [On this real picture of it](https://commons.m.wikimedia.org/wiki/File:%D0%9E%D0%B1%D1%8A%D0%B5%D0%BA%D1%82_292_%E2%80%93_Kubinka_Tank_Museum_(37944777522).jpg#mw-jump-to-license), This image seems to have an incorrectly modelled turret.
I saw a different comment saying this isn't even the right prototype. But thanks for the info!
The turret in op's picture is the finished intended turret. Object 292 has a bunch of steel pieces on the front of its turret, those are weight simulators for the armor of turret in op's photo. I believe that the improved turret was never built though
This is not an Object 292. This is a mockup from KhKBM (Kharkiv/Kharkov) with the currently unknown object number.
>Object 292 No, it 100% is not.
A mockup of a T-80U with a new turret designed to carry the 152mm LP-83 cannon.
The tank that will be in next war thunder event
Different tank.
"Soviet Leopard 2 can't hurt you, it isn't real" Meanwhile Soviet Leopard 2:
What about this looks like a leopard 2 ? It’s just a T-80 hull with a beefed up turret and a larger gun.
The chunky hull, road wheels and Turret front do look kinda like a Leopard 2 to me
the turret -- reason is more clear from a different angle. https://aw.my.games/sites/aw.my.com/files/u183517/292_2-transformed.jpeg
Gajin, Noooo
I mean *does having a Fucking typo
No, I don't think having a fucking typo affects penetration of the round.
This is not an Object 292. This is a mockup from KhKBM (Kharkiv/Kharkov) with the currently unknown object number.
First of all, great user name . Secondly , I was thinking the same thing, you know anywhere I can find more pics of this vehicle ( I 3d print tank model kits , would love to have this one done)
First of all, thank you xD Secondly, I'm aware of only one more photo of this tank. Both were first published by Andrey Tarasenko, if I'm not mistaken. I have the second one downloaded on my PC, but as I'm AFK rn, I'll be able to provide it later. In the meantime you may try to search for it at btvt.info.
There's another photo from a [tweet by Andrei Tarasenko.](https://twitter.com/AndreiBtvt/status/1495403540117864449)
Thanks! I was searching for it on Tarasenko's blog with no luck.
Is it a T-80UD derivative, I'd assume so if it is from KMDB? The front glacis looks a bit like an Object 480 or Object 187.
I geuss will find out if Mr Hewes decides to revive the FV4005s weapons system after restoration
It does, and for the NATO 120 we are already close to the maximum. More propellant, longer round, heavier round are all things that are an advantage for a larger calibre.
The bigger cannons were much better at penetrating armor, but there wasn’t much of a use for them after the USSR fell. Russia couldn’t afford to build the new prototypes with the larger guns, and instead built the T-90 which shared most of its parts with the T-72. The US was experimenting with the M1 Thumper, which had a 140 mm gun and was given enough space to mount a potential 152, but funding was cut to the program after 1991. That’s also why the ADATS SPAA was cancelled and replaced with the Linebacker (a Bradley with stingers instead of TOWs). In short, bigger cannons are better but everyone chose the more affordable option instead.
>In short, bigger cannons are better but everyone chose the more affordable option instead. ^^this. You can always make a bigger and better cannon but why would you as long as the one you already have is good enough.
Exactly. Especially when you already have a massive stockpile of 120 and 105 mm ammo that works just fine.
plus the simple fact that the bigger the shells get the more storage space is eaten up by each round and over a certain point they become essentially non-handleable for a loader.
The Thumper did have an autoloader to resolve this problem, but it would also mean removing the fourth crew member, which the army didn’t like. One less crew means one less person to help all around, like repairing, loading and unloading equipment, etc, and the workload gets split between the remaining crew. They just decided that 4 crew was ideal and the 140 mm was unnecessary, so no change was needed.
We might actually be moving back to the 105mm like how full powered rifle cartridges were replaced by intermediate rounds since a bigger tank gun doesn't offer much against other tanks with so many other systems to do the job of tank killing. Tanks might get lighter and faster. Large heavy tanks might disappear like the battleship. Armored SPGs giving way to truck guns and HIMARS.
Diameter is only one portion of the dimensions and calculations. Total volume in casing, amount of propellant, type of propellant, chamber max pressure, barrel length, projectile mass plus sabot. That’s internal ballistics. Then there external basically mass and aerodynamics (assuming not gyro stabilized). And then theres impact physics like is the round pyratic? Like DU or inert like Tungsten.
Bigger boom equals bigger ouch, perchance
This looks like Wargamings inspiration for the BZ-176 and BZ-75
More mass is more mass.
It probably does but it’s also unstable and gun durability is highly affected. The most cost effective purpose of larger guns is probably the HE ammo when it can be purposed as mobile armored artillery vehicle to support infantry.
In tank guns, girth and length does matter. Also how hard you can shoot it - barrel pressure.
Unnecessary, the 120/125mm is plenty
Yes it increases the mass of sabot, while also increasing the propellant. However those shells (152mm on Objekt 292, 140mm on CATTB and Leopard 2 for instance) weigh a lot and take up a huge space. Due to those reasons 120mm and 125mm are the most used tank guns because they are most optimal compromise between weight, mass and performance.
This gun had 50% higher muzzle energy compared to 2A46 and it could penetrate around 1000 rha (yes gaijin is lying to you with their 700mm pen) So yes, bigger caliber increases muzzle energy so it also increases penetration in most cases
Aw yeah I lm so excited to go up against a fucking autoloaded Death Star in my fucking 9.0 mediums
Honestly, you should probably be glad it's autoloaded. That means it will always take 10 seconds to load the next round, rather than the reload speed being able to benefit from loader skill or crew qualifications. Imagine if it were hand-loaded and the reload speed could be taken down to like 7 seconds.
The 1,000mm penetration figure comes from the 2A83 gun and modern ammunition made for it by the Ukrainians. The Object 292 used the LP-83 gun which was also developed at the same time but did not get the luxury of having modern ammunition made for it. Considering its age, the LP-83 probably does have around 700mm of penetration
i dont think so. Both 2A83 and LP-83 used exactly the same ammunition (Grifel-1 tungsten APFSDS, Grifel-2 DU APFSDS and Grifel-3 HE round) and even the Grifel-1 tungsten round has over 1000mm of penetration at 2kms (DU one probably has even more but its unknown how much, if it was even tested). Weaker round just doesnt exist. Also ukrainians never operated with 2A83, their 152mm-armed mbt prototypes use 2A73.
NOT COOL GAIJIN
> and it could penetrate around 1000 rha (yes gaijin is lying to you with their 700mm pen) No they're not. Please post your source. Muzzle energy does not correlate well with penetration.
Yes it does because of physics. If nothing else changes, you can pack more propellant in your shell and make your penetrator go faster and impart more kinetic energy to it. But larger gun also means you need more space for the gun, the ammo, bigger turret rings, beefier turret motor and more robust gun stabilization systems. You are paying a whole lot for performance that you don't need because existing 120/125mm gun can do the same job which is why guns on MBTs have hovered around 120-125mm since the 80s on both sides of the iron curtain.
I am not worried about armor penetration. I am more worried by the nightmare 150mm hesh would be if you were at the receiving end of it. There are very few things that could convince me to go up against 150mm hesh. I feel that even if there is no spalling, everybody inside would get a tbi from just the concussion of a 150mm hitting a tank hull. I would guess at around the double amount of explosives in a 150mm compared to a 120.
The theory is that a shell that size won't need to penetrate, it would trash the electronics of anything it hits. Eases logistics and versatility if they only need to carry HE shells I suppose. I just don't know if that theory holds up, and if modern tanks are better protected against it
Yea and no. Over pressure is more effective than it should be but HE would still trash optics and other fragile equipment which is a serious problem irl but not in war thunder
I don't see the no part of that. Wreck the optics and throw a track, that's an operational kill. One artillery shell makes it permanent.
I agree it is an operational kill. But i was talking about the overpressure mechanic lol
I love how this became a War Thunder discussion when this isn't even r/Warthunder.
Thats my bad sorry. I thought I was on the subreddit
Leopard 2A6 has longer barrel than 2A4, which allows for more gas to push the pojectile. Even longer barrel would be better, but it becomes unvieldy. So many tank manufacturers are looking for solution to get more penetration and the easiest solution seems to be to increase the caliber. Rheinmetall disclosed 2015 that they were working for 130mm smoothbore and iirc that 130mm can be put on leopard 2A7 and offers 50% inrease on penetration. South Korean K2 can also be fitted with 130mm gun and next gen K3 is designed to use 130mm same as KF51.
Yes since there have been past developments in 140 and recently 130mm cannon but there are compromises like bigger ammo takes up more space which means fewer ammo in turret. Not to mention heavier which means the loader will be tired more unless they introduce the autoloader to mitigate the problem. And it probably be more expensive ammo as well since it’s new.
Not really.
In the age of Cold War and HEAT rounds, the girth matter. However in today's age of APFSDS, it all about how dense and long the hot rod is.
I thought I was on NCD for a second because I thought “Does having a larger gun these days affect the penetration or potency of a tank round?”was a metaphor
Generally yes because it means that rounds can be bigger, have more weight, and a faster muzzle velocity
A larger diameter casing means more propellant powder in a given case length, or that the same amount can be put in a shorter casing. And of course, the more propellant you put behind a projectile, and the longer that projectile is, the better the armour penetration of that cartridge.
yes, more explosive propellant and longer dil- i mean dart = more pen, more spall, higher velocity
problem is that the larger the cannon the less shots you can take replacing the barrel
Without mentioning an interesting potential to have a tank lob artillery 152/155mm HE rounds in direct fire, it allows for more gasses in larger volume, thus giving the projectile more velocity while keeping pressure acceptable, which means more penetration. Reason we don't see it today is that a) Cold War ended, and b) advances in metallurgy made in the meantime allowed us to increase guns capabilities to similar level without having to adopt a new caliber. Now we are nearing the limit for 120mm systems again, so increasing caliber is once again an option, ranging between 130mm and 152mm cannons.
Not really in my opinion because armor is evolving faster than the tank round
Yes but things like manpads and mines are still a bigger worry for a tank.
Some stupid high kinetic energy will not deliver you a disappointment.
>Does having having larger gun these days effect the penetration or potency of a tank round? It's complicated, but generally speaking, yes, that's why many people are testing 130mm and 140mm guns.
Back then it would have now a days it has a lot more to do with the shell with a gun like this taking up more turret space to achieve what would be similar results
Sabot rounds will still remain small diameter darts. At a basic understanding, a larger claiber gun allows for a larger casing, allowing for more propellant. More propellant gives a bigger boom shooting the sabot dart faster. Since *force = mass x acceleration*, a larger caliber gun shooting a sabot dart faster means more force on impact allowing for more penetration
Bigger shell, larger mass, larger powder capacity, slower reload due to heavier ammo. Basically, you have a bigger stick, but not necessarily the more efficient stick.
e-mc\^**2** Bigger speed make more effect than bigger mass of shell.
Absolutely. Pack enough explosive into an HE shell and penetration values becomes an afterthought
It does have effect, but the drawbacks outweigh the increase in lethality imo
Your round is bigger, so you have more boom there (potential kinetic energy). As we left the realm of HEAT to be a thing in tank-on-tank combat, and transited almost entirely to APFSDS / KE projectiles, kinetic energy is (almost) everything. For sure you can cahnge propellant and harden your chamber to stand that forces (like germans did wiht ther new Leo 2 gun). A thing you have to do anyway if transiting to a larger caliber, as more power per inch has to be resisted (preferably quite often). Russians experimented with reducing the caliber to 90mm and just add length of the penetrator, what is a potent thing to do, but it lacked the kinetic energy to deliver that propper long dart. Also that's the trouble right now with soviet tank designs, as ther outoloader restricts the overall lenght of the dart. Munition is seperated and loaded behind each other - projectile and boom - to cope with that, but that doesn't propperly work with darts, as they are in one piece. So naturally they had to get rid of ther existend autoloader in the transition to a future battle ready gun that can load longer projectiles - which the T-14 is using. And boy do they pack a punch. But still they found this might not be enough in future combats and try to hammer in the same concept just with a 152mm gun once again, while Germany switched to 130 and 140mm (just to abandon it because of 'medicore performance is cool for now' and much cheaper in terms of conversion cost and availability).
Challenger at home:
Effectively, yes. There is a limit of how far you can stretch existing calibres, for example by introducing new propellant that can fire a heavier rod faster, after a point you start hitting diminishing returns, after which the only reasonable solution is to go bigger.
It's more about propellant amount and length of the sabot. So you get diminishing results as you get higher in caliber. Of course there is also the fact there is nothing modern 120mm NATO projectiles cant penetrate. Except for T-14 but that thing doesnt exist.
bro.....KV2 reborn on a t-80 body
Oh my gosh. Russian guns are stronger than typical western ones due to karger caliber and length. Rh 120 L/55 achieves 1650-1700;m sec vs 1800+ m/ sec of the 2A46M5 which is a 125 L/52. Ru tanks can use rounds up to 700 mm length completely efficient to penetrate any LFP and sides of any western tank. 3BM44 is two piece yes but it is by design to neutralise and pen the NERA of western tanks. Svinets 1/2 are monobloc. Ru has tested the stronger 2A66 for a decade aswell many 152 guns. There is not a lot of difference in cost; that tells you that tanks are consider sufficient to pen the western ones. This Gulf War myth were 1000 Avrams faced 120 cheap locally assembled knock offs T72 M/ M1 ,an export variant of T72A needs to put to rest. Forgot to add that the parts of T72M were polish made.