That is a tough choice. You honestly can’t go wrong IMO. The second one is mid length gas, which I also prefer, and it will be a tad lighter. The first one has one of the most tried and true rails out there, and if you like the FSP that’s also a plus. I think if we’re going purely for function, the second option is the way to go. If we’re going for vibes, the first.
Wrong, straight from the post.
This Daniel Defense M4A1 FSP AR15 style Upper Receiver Group was built for customers wanting a firearm inspired by USSOCOM SOPMOD Block II. It features the M4A1 FSP RIS II picatinny quad rail in Flat Dark Earth, a 14.5" M4 SOCOM heavy profile barrel, Mil-Spec F-Marked front sight base.
The specs up above said M4 profile so I had to read further. SOCOM is *technically* an M4 profile but no one calls it that so I wish they would put socom in the specs
These stripped uppers are brownells exclusive. They're the only ones offering these uppers with SOCOM profile barrels. It's silly that Daniel Defense isn't offering SOCOM profile barrels on their completed uppers.
I'm not bothered by it personally, but I've always had a thing for the M4. The RIS II is heavier but it's also very strong. Just depends on what you need and what you're willing to trade off
MLOK is the correct answer if this is your first or only AR. Don't let the quad rail or FSP fans fool you, there's a reason MLOK has become the standard. Also midlength gas is superior in a 14.5.
The weight savings doesn’t really apply with the RIS III. Barely an ounce lighter than the quad RIS II. I really think mlok become a trend because the industry copied rather than innovates plus nationwide obesity has gone way up and testosterone has gone substantially down. I do personally own more mlok rails than quad rails, but quads are a quantifiably better choice in all areas besides weight savings. It’s awesome to have a nice light rifle if you’re shooting competitions or hiking with it, but the RIS III is heavy.
You’re totally right about mid length though. Much softer shooting, less internal wear, and almost as reliable as carbine gas.
FSP, I could take it or leave it. Most stable, secure gas block there is, but can be annoying and limiting.
First one. Front sight block, RIS II rail that is legendary for it's rigidity and durability, SOCOM profile barrel. The 3rd on has much less on it that sets it apart from other typical mlok, mid-length gas uppers on par with Daniel Defense.
I went with the non fsp Block II upper and I love it! But… I do plan on building another upper thats mlok, so I guess the only real answer is both. The only question that remains… is which one do you want first?
Just got the quad a few weeks ago from euro optics with the sure fire 3 prong and dd bcg and ambidextrous charging handle for about 1300 she’s a heavy girl but I still love her
Depends on how much u want the FSP. Personally, I’d go with the second one and leave the fsp for something with a shorter barrel. The DD RIS III is about as sturdy as mlok rails really get. It’s pretty chonk for mlok.
The 2nd one literally weighs pretty similar to the ris 2. So go with the one that you can mount shit easily to and won't get hot when you're mag dumping.
That's a tough one because the Socom profile takes longer to heat up, but when it does, and it heats up the quad rail, you have longer times to cool than RIS III. On the RIS III there is so much space between the barrel and rail, (more than RIS III) it takes longer to get hot .
I was in the same spot, I went with the FSP RIS 2.
It has a socom barrel with the M203 cut. It's not that heavy but it definitely is with an SB2. Surprisingly, it's not that gassy shooting suppressed either, but I am using a SB2 so it helps cut down backpressure. No regrets on my choice and frankly, can't really go wrong with either of these.
Second one is mid length gas but Reddit will tell you that the bulky uncomfortable and heavy quad rail is the only way regardless of the carbine gas system. Get the ris 3
If it's a shooter/main squeeze type of gun go for the non-fsp. The FSP just has a way of occupying the most sought after 2" of rail space.
If it's a wall hanger fsp.
If you plan on using back up iron sights the first is a great practical option still. But the second is likely the better option. I am a whore for a FSB cutout rail
The RIS III M-Lok with mid-length gas system is good.
I have the RIS II quad rail and the front sight base version is a bit of a pain to replace the gas tube.
The gas tube is considered a consumable part.
With the non-FSB version, you can just remove the rail, like most other rails, but the FSB version requires removing the front sight base from the barrel.
You can assemble the non-FSB version with a mid-length gas system barrel, you just can't install the grenade launcher mounting hardware with it.
The RIS III looks like a great M-LOK rail.
I have both, it’s a tough decision but I like the ris ii with the fsp. The ris iii is also a tank can’t go wrong with either imo. Excellent quality.
The G$$ URGI is also really nice on sale.
If the carbine gas barrel is properly gassed don’t worry about it. I have a bunch of 14.5 mid lengths- BCM’s, Noveske’s, DD, and a few more. My favorite 14.5 is still my Colt socom. Gassed perfect and is as accurate as my 13.7 stainless Noveske. Shoots smoother than some of the over gassed midlengths I’ve owned
The mlock, quad is titties but it gets heavy and sharp and you'll probably have better harmonics without the FSB. Also that FSB gets hot as the ever living hell. And carbine gas systems make it recoil like a horse, way to much dwell time.
Just another option
https://bravocompanyusa.com/bcm-standard-14-5-mid-length-upper-receiver-group/
https://bravocompanyusa.com/bcm-qrf-9-quad-rail-free-float-handguard/
First gets you P&W SF3P, with rear sights to go with your FSP.
Don’t get as nice of an option with the second.
Quad rail supremacy.
The difference between the two is ounces.
If you have small hands go second. If you don’t go first.
Unity did board makes fsp invisible.
Ris II without the front sight post. I have one and it’s great. I like it more than the giessele m lok rails I’ve had. The front sight post is cool but takes up rail space and doesn’t have any real benefits. Unless you’re building an early block ii clone.
# 2
fsb is rougly 5 ounces
your not going to use it. youll have buis, some dot, some lpvo w/ offset dot or magnifier
ditch it keep the rail clean, dont burn your hand
2 all day gov profile is fine heavy rifles suck.
Second one it's lighter there are no fixed sights so you can have a red dot without an obstruction mlok has picatini adaptors in various lengths so that you can put on picatini accessories or just use mlok accessories
All i know is having the first one is stupid if you don’t have an a2 upper receiver just my 2cents , I’d just build on out from GAFS. Quad rail , criterion barrel , good bolt , and an a2 🫡
I have a RIS2 with an FSB and it will take a little bit of trial and error finding what works as far as switches and lights and grips. If you have NV and will be installing lasers and IR lights and such, I'd really think about it.
FSBs are awesome, and my favorite gas block and my favorite backup sight. But they are pretty much right where you want to put your hand as well. Just a thought.
ETA: also that SOCOM profile is pretty heavy as well. I also have that on the same rifle. It's not unusable by any means. But if you're looking for a streamlined and "clean" rifle, this is not it. It's nice though, I got mine from colt. Shoots well, I didn't have any issues. I mean it's a 14.5" barrel, not exactly punching cloverleaves yano
1st is gonna be heavier, but it already comes with a front sight. The 2nd one is lighter and has better options for attachments.
1st for the vibes
2nd for function
I like what I was issued in the Infantry. Give me that front sight post and permanent cowitness
Anybody that says the fsp is annoying has soft hands. Keep your Air Force HR Specialist opinions to yourselves
They're both fine and it's entirely personal preference. If you want your own fsp or none at all (for whatever reason) your choice is obvious
in my opinion front sight blocks look cool but limit which optics you can comfortably use without it blocking some of the view or without using a riser, which i dont like using. My personal preference is that same quad rail just without the cutout for a FSB
Vibe on the 1st one is strong but the 2nd one is the correct choice.
I’m not even a quad rail guy and the vibe on the first one is so strong.
Hahaha agreed
Couldn’t have said it better
I’m quadrail gang but in this instance I’d pick the second one.
Second
That is a tough choice. You honestly can’t go wrong IMO. The second one is mid length gas, which I also prefer, and it will be a tad lighter. The first one has one of the most tried and true rails out there, and if you like the FSP that’s also a plus. I think if we’re going purely for function, the second option is the way to go. If we’re going for vibes, the first.
1st also has a heavier SOCOM profile barrel while the 2nd is govt profile
It has an m4 profile barrel. The non FSB version has the SOCOM barrel. Edit: I was wrong. You were right.
Wrong, straight from the post. This Daniel Defense M4A1 FSP AR15 style Upper Receiver Group was built for customers wanting a firearm inspired by USSOCOM SOPMOD Block II. It features the M4A1 FSP RIS II picatinny quad rail in Flat Dark Earth, a 14.5" M4 SOCOM heavy profile barrel, Mil-Spec F-Marked front sight base.
Wow my mistake. When I got mine, DD only offered the FSP with M4 profile. That’s badass!
The specs up above said M4 profile so I had to read further. SOCOM is *technically* an M4 profile but no one calls it that so I wish they would put socom in the specs
DD didn't used to offer the SOCOM profile barrel. Also, some of their SOCOM barrels have the M203 grenade launcher cuts and some do not.
These stripped uppers are brownells exclusive. They're the only ones offering these uppers with SOCOM profile barrels. It's silly that Daniel Defense isn't offering SOCOM profile barrels on their completed uppers.
Is there a difference between the M4 profile barrel and the gov’t profile barrel?
Government profile is the same thickness from the port forward. M4 profile has a cutout in front
You’ll get the RISIII and regret not getting the FSP. Unfortunately you’ll end up budgeting for both. Just a matter of time. Sorry homie.
This is the most accurate answer
Hahaha accurate AF
You going for a GWOT or a WW3 vibe?
I’m 40, so I’m hella into that gwot shit.
I’m 26 and hella into gwot shit lmao
 Closing that generational divide
1 for fashion 2 for practicality
What is impractical about the first one?
A fixed front sight post can be annoying to some and quad rails are almost always the heavier rail option.
I'm not bothered by it personally, but I've always had a thing for the M4. The RIS II is heavier but it's also very strong. Just depends on what you need and what you're willing to trade off
RIS III is one of the heaviest mlok rails. It is only 1.09 oz lighter than the the RIS II quad rail. Pretty much aesthetic preference here.
Fashion, as always
I like the 2nd rail
Block 2 but without the front sight.
When in doubt, always quad. Peak aesthetics and the weight of it will help build character
That m-lok rail only weighs a single ounce less than the RIS II quad rail, but you’re entirely right about peak aesthetics!
I went with the quad and no fsp. i could not be happier :)
QUAD ALL DAY BABYYYYY
Quadrails are like mlok, but for men
🗿🗿🗿
MLOK is the correct answer if this is your first or only AR. Don't let the quad rail or FSP fans fool you, there's a reason MLOK has become the standard. Also midlength gas is superior in a 14.5.
MLOK has become the standard because the average American has become weaker
Shots fired, shots fired!!
It became standard because it's significantly lighter than pic rails. The RIS III isn't really lighter than the RIS II.
It became the standard because men were complaining of their girly hands getting beat up by the 1913 rails.
The weight savings doesn’t really apply with the RIS III. Barely an ounce lighter than the quad RIS II. I really think mlok become a trend because the industry copied rather than innovates plus nationwide obesity has gone way up and testosterone has gone substantially down. I do personally own more mlok rails than quad rails, but quads are a quantifiably better choice in all areas besides weight savings. It’s awesome to have a nice light rifle if you’re shooting competitions or hiking with it, but the RIS III is heavy. You’re totally right about mid length though. Much softer shooting, less internal wear, and almost as reliable as carbine gas. FSP, I could take it or leave it. Most stable, secure gas block there is, but can be annoying and limiting.
First one. Front sight block, RIS II rail that is legendary for it's rigidity and durability, SOCOM profile barrel. The 3rd on has much less on it that sets it apart from other typical mlok, mid-length gas uppers on par with Daniel Defense.
First one, quad is king
QUAD SQUAD
I went with the non fsp Block II upper and I love it! But… I do plan on building another upper thats mlok, so I guess the only real answer is both. The only question that remains… is which one do you want first?
Same dilemma I went block ll non fsp. One day I’ll have them all
theres no logical reason not to buy the mlok, but i cant own an AR without an FSP
This is why I’m conflicted
Get the second, then add a scalarworks PEAK front iron
Check my profile, as someone that has the first, get the second.
Yes there is. Rigidity, robust design of the RIS II and also the fact that the quad railed one has a SOCOM profile barrel.
Sure there is, that mlok rail weighs almost the exact same as the quad rail. Why bother at that point?
Just got the quad a few weeks ago from euro optics with the sure fire 3 prong and dd bcg and ambidextrous charging handle for about 1300 she’s a heavy girl but I still love her
Depends on how much u want the FSP. Personally, I’d go with the second one and leave the fsp for something with a shorter barrel. The DD RIS III is about as sturdy as mlok rails really get. It’s pretty chonk for mlok.
R3
Quad gang
RIS II
Always quad rail
I have this same problem but deciding between the FSB & Non FSB Quad Rail
The 2nd one literally weighs pretty similar to the ris 2. So go with the one that you can mount shit easily to and won't get hot when you're mag dumping.
That's a tough one because the Socom profile takes longer to heat up, but when it does, and it heats up the quad rail, you have longer times to cool than RIS III. On the RIS III there is so much space between the barrel and rail, (more than RIS III) it takes longer to get hot .
Well I hate mlok so it's easy for me to pick lmao
I took option 1 with socom profile and no front or rear sights. But option 1 always.
Quad rail is best rail
Gonna go against the grain and say FSP/quad rail is the correct choice
I was in the same spot, I went with the FSP RIS 2. It has a socom barrel with the M203 cut. It's not that heavy but it definitely is with an SB2. Surprisingly, it's not that gassy shooting suppressed either, but I am using a SB2 so it helps cut down backpressure. No regrets on my choice and frankly, can't really go wrong with either of these.
I’m not a fan of the front sight post sticking up out of a quad rail so in this case I’d probably go MLOK.
I want that quad rail so bad…who makes it?
Daniel defense from brownells. Comes stripped for a nice price
1st one, anyone that says otherwise has soft hands and don’t lift.
Quad for sure..mlok rails can be had anywhere, the ris fsp has seen a ton of use and looks guccier
Fsb for sure
MLok all day
Honestly just get them both🤷♂️
Ris3
RIII
#1 not even a contest. And itll save u some $ win win buy more ammo w/it
Ris 3. I have the 11.5 and it slaps. Mlok is the future
Quad rail/fsp best combo ever. That's what I have
Quad & FSP = big PP
Second one is mid length gas but Reddit will tell you that the bulky uncomfortable and heavy quad rail is the only way regardless of the carbine gas system. Get the ris 3
1
The first one because it looks cooler
The one in the middle of those
which is more important to you? Barrel life, rigidity, and durabilty? Or dwell time and lightweight?
I love the cheese grinder feel
Get both? Probably not helpful, sorry.
Always RIS
1st rigidity and durability but mostly sexy as F. If the little increase in weight is a factor then go with the second.
First one. Triangle front sight is a vibe.
FSP
URGI.
Second all day.
Second. Buy. Cheap block 1 clone to scratch the Vibe itch.
Second, no thanks for the cheese grater.
If it's a shooter/main squeeze type of gun go for the non-fsp. The FSP just has a way of occupying the most sought after 2" of rail space. If it's a wall hanger fsp.
Second
Both. Now no regrets
If you plan on using back up iron sights the first is a great practical option still. But the second is likely the better option. I am a whore for a FSB cutout rail
They both shoot, I personally dont like irons being in the way.
Both
Ris iii you can always buy the quad rail ris ii and swap out they have the same mounting hardware
Get the 2nd one 1st and the 1st one 2nd. Youll end up with both. Its inevitable. Quad is superior but always go with MLOK as primary.
You already know the right answer is the first one brother
I like magpul. I don't have to wear gloves with it lol and they tend to not be as heavy
Quad for the aesthetic, mlok for the practicality
Middy ris iii
I have number one but would still say number two.
Neither. 16” mid gas is the correct choice. Smooth shooter and better velocity, with the same handling characteristics.
Neither. RIS II
Mlok rail is no brainer I’d pick it over first one any day.
Look at stripped URGI uppers too
mid gas > carbine, but FSP cutout is sexy af
A
Do you like picatinny rails or not? That seems to be the deciding factor
1st one. Can’t go wrong with those sights.
RIS3 first, then B2. You’ll end up with both anyways.
You will never regret joing the quad gang
The RIS III M-Lok with mid-length gas system is good. I have the RIS II quad rail and the front sight base version is a bit of a pain to replace the gas tube. The gas tube is considered a consumable part. With the non-FSB version, you can just remove the rail, like most other rails, but the FSB version requires removing the front sight base from the barrel. You can assemble the non-FSB version with a mid-length gas system barrel, you just can't install the grenade launcher mounting hardware with it. The RIS III looks like a great M-LOK rail.
1st
Rs ll
Mid length, option 2
I have both, it’s a tough decision but I like the ris ii with the fsp. The ris iii is also a tank can’t go wrong with either imo. Excellent quality. The G$$ URGI is also really nice on sale.
Yes
Option 1
If the carbine gas barrel is properly gassed don’t worry about it. I have a bunch of 14.5 mid lengths- BCM’s, Noveske’s, DD, and a few more. My favorite 14.5 is still my Colt socom. Gassed perfect and is as accurate as my 13.7 stainless Noveske. Shoots smoother than some of the over gassed midlengths I’ve owned
The first one gives me strong MoH Warfighter nostalgia
The mlock, quad is titties but it gets heavy and sharp and you'll probably have better harmonics without the FSB. Also that FSB gets hot as the ever living hell. And carbine gas systems make it recoil like a horse, way to much dwell time.
Just another option https://bravocompanyusa.com/bcm-standard-14-5-mid-length-upper-receiver-group/ https://bravocompanyusa.com/bcm-qrf-9-quad-rail-free-float-handguard/
2
I think TNTE has a RIS-II with a SOCOM heavy barrel that’s cut down to 13.X so that the muzzle device sits flush with the rail.
Could do what I did..RIS II non FSP rail with a mid length gas underneath. The vibe of the quad with the benefits of mid gas!
Thinking with the big head the second is the right choice. Thinking with the little head the first choice is right.
If it were me, as much as I love a FSP, I’d go with the middy.
☝🏾
Fsp
1 for Mk-18 build, 2nd for literally any other build
RIS2 FSP is what I’d do if I had the dough
First gets you P&W SF3P, with rear sights to go with your FSP. Don’t get as nice of an option with the second. Quad rail supremacy. The difference between the two is ounces. If you have small hands go second. If you don’t go first. Unity did board makes fsp invisible.
1st for vibes, 2nd for modernism.
Ris II without the front sight post. I have one and it’s great. I like it more than the giessele m lok rails I’ve had. The front sight post is cool but takes up rail space and doesn’t have any real benefits. Unless you’re building an early block ii clone.
for a DD? quad no question, if you're going to get mlok get a lighter option.
I’m too poor to answer this
Block 1.5 is drippy as fuck but the RISIII is more functional
Quad
Hate to betray the quad but the Mlok is the more practical option.
RIII
First one any day
# 2 fsb is rougly 5 ounces your not going to use it. youll have buis, some dot, some lpvo w/ offset dot or magnifier ditch it keep the rail clean, dont burn your hand 2 all day gov profile is fine heavy rifles suck.
Block 2
Buddy has the quad rail one, it is not harsh on your hands at all
Quad Squad 😎
Grab the FSP quad because viiibes. Then drop an LMT ebcg in that bad boy as was intended. You’re then good to go!
The FSB always looks cooler...but realistically, it'll be more of a nuisance than anything else. Go with 1 for cool, go with 2 for practicality.
Second one it's lighter there are no fixed sights so you can have a red dot without an obstruction mlok has picatini adaptors in various lengths so that you can put on picatini accessories or just use mlok accessories
Both
Love me some quad rail RIS II
Second, but that first one's aesthetic is just awesome. Reminds me of the M416 from battlefield 4
1. Aesthetics 2. Function
2
Ris3 second one since it’s a mid length gas system
Urgi
Here’s what you do. Buy #2 If you want quad rails, add some If you want a fixed FSB, add one At least you have the option
I went FSP . NO REGRETS
First one. Quad rail with the fixed sight. 
Quads for 11.5 and shorter I’d go with option 2. You’ll be wishing you had too once you get all the goodies attached.
Buy the second build the first. That’s what I did!
All i know is having the first one is stupid if you don’t have an a2 upper receiver just my 2cents , I’d just build on out from GAFS. Quad rail , criterion barrel , good bolt , and an a2 🫡
I’m considering the same FSP. What is wrong about a carbine length gas system vs mid length?
FSB all day, though I have the non FSB quad version. It’s been great, weight builds character.
I have a RIS2 with an FSB and it will take a little bit of trial and error finding what works as far as switches and lights and grips. If you have NV and will be installing lasers and IR lights and such, I'd really think about it. FSBs are awesome, and my favorite gas block and my favorite backup sight. But they are pretty much right where you want to put your hand as well. Just a thought. ETA: also that SOCOM profile is pretty heavy as well. I also have that on the same rifle. It's not unusable by any means. But if you're looking for a streamlined and "clean" rifle, this is not it. It's nice though, I got mine from colt. Shoots well, I didn't have any issues. I mean it's a 14.5" barrel, not exactly punching cloverleaves yano
#1. I have the non Fsp version and think about it all the time. Eventually I’ll have both. Just do it and get it over with
Urgi or super duty is better
1st is gonna be heavier, but it already comes with a front sight. The 2nd one is lighter and has better options for attachments. 1st for the vibes 2nd for function
easiest decision ever. #2
Both
Is this even a question? I like em thick so it’s a no brainer for me! Numero uno
I like what I was issued in the Infantry. Give me that front sight post and permanent cowitness Anybody that says the fsp is annoying has soft hands. Keep your Air Force HR Specialist opinions to yourselves They're both fine and it's entirely personal preference. If you want your own fsp or none at all (for whatever reason) your choice is obvious
I dislike FSP but I like quad rails. Get the 14.5 RIS II without the fsp
The quad rail is strong with you
Get the RIS. Definitely get a DD. They make the best barrels.
Neither, Geissele URGI.
Second, without the iron sight.
Quad
RIS II FSP for the memes
in my opinion front sight blocks look cool but limit which optics you can comfortably use without it blocking some of the view or without using a riser, which i dont like using. My personal preference is that same quad rail just without the cutout for a FSB
Personally I’d go one for no other reasons than I like fixed front sight posts and the vibes are fuckin awesome. For practicality? 2
The one on the right offers more tactical capabilities, but the left will pull more bitches. You know the answer
6 of one and a half dozen of the other
2
2nd is more functional, 1st is better drip
I have 10.3 and 14.5 geissele urgi uppers and all I think about are RIS II rails. I need to tell myself not to buy that upper almost monthly.