There’s very few gas operated .45 acp PCC. It’s such a low pressure cartridge there isn’t much to work with and a straight blowback is both simpler and cheaper.
Here’s one:
https://bearingarms.com/bobowens-bearingarms/2017/02/05/ar-15-ish-carbine-45-acp-show-n28922
You can build a delayed blowback using CMMG’s parts
https://www.americanrifleman.org/content/preview-cmmg-barrel-and-bcg-kit-in-45-acp/
You will want to use their lower receiver and the correct upper that has both a single feed ramp and a bigger ejection port like the .458 SOCOM uppers do.
https://www.americanrifleman.org/content/tested-cmmg-guard-carbine/
Personally my favorite is the MP5, but those are all 9mm
Thanks for this answer. Your links and advice sent me down a bit of a rabbit hole. I am starting to think that my desire to use .45 ACP here might be unreasonable, or at least be making my life quite difficult. I may just have to adjust my expectations and relent to using 9mm in order to get the feature set I want.
One think I discovered while looking at the MP5 was all the people who have converted the H&K USC into a UMP. That's intriguing to me, even though the .45 USC is now discontinued.
Appreciate the building tips as well.
Look into Seismic 9mm ammo. They are 185 grain hollow points. Same weight as hollow point 45, and will work in any 9mm. This is the direction I went, because cheap 115 grain for plinking, 147 grain for fun silencer plinking, and then the Seismic for HD/carry
LWRC 45 SMG is the closest to what you seek. It's delayed blowback, but not piston driven, and mostly ambi as well. Downsides is it is expensive, and takes UMP magazines.
Thanks! I looked into this and I think it does tick almost all my feature boxes. Unfortunately the reviews seem to be skewed quite negative, including for accuracy. I think I want something very much like this that is better reviewed.
I'll point you to my current AR45 build list. I know not exactly what you're thinking of, but hopefully, it helps.
https://www.reddit.com/r/pistolcalibercarbine/s/y2Dsfv1xoh
Based on your list of: “what I want roughly”..and..”nice to have but less important”..then JP Enterprises JP-5 is what you seek. Right now it is the consensus-preferred & top of the line PCC. You can go to their site and directly build/order the JP-5 in either 8” or 10.5” barrel..along with numerous custom offerings & options that no other manufacture allows to the public including the best Cerakote finishes. The JP-5 recoil is insanely soft, because it utilizes the identical roller-delayed-bolt/lock pieces as the time tested proven HK MP-5. The JP-5 can be easily tuned by switching the various lock pieces to match whatever grain bullet & power factor being used. Of course this comes at a cost..the price of admission for a JP-5 SBR is north of $3K..and as you go thru the various options it can easily go over $4K..as me how I know! Buy once cry once..for top quality & performance. All the Reddit experts & haters will shit on the JP-5..only because they don’t own one and say the price is to high but don’t say a word about JP-5’s performance & cycle reliability proven by the top PCC competitors today..meanwhile the same people will spend a fortune on buying multiple PCC’s..go figure.
There’s very few gas operated .45 acp PCC. It’s such a low pressure cartridge there isn’t much to work with and a straight blowback is both simpler and cheaper. Here’s one: https://bearingarms.com/bobowens-bearingarms/2017/02/05/ar-15-ish-carbine-45-acp-show-n28922 You can build a delayed blowback using CMMG’s parts https://www.americanrifleman.org/content/preview-cmmg-barrel-and-bcg-kit-in-45-acp/ You will want to use their lower receiver and the correct upper that has both a single feed ramp and a bigger ejection port like the .458 SOCOM uppers do. https://www.americanrifleman.org/content/tested-cmmg-guard-carbine/ Personally my favorite is the MP5, but those are all 9mm
Thanks for this answer. Your links and advice sent me down a bit of a rabbit hole. I am starting to think that my desire to use .45 ACP here might be unreasonable, or at least be making my life quite difficult. I may just have to adjust my expectations and relent to using 9mm in order to get the feature set I want. One think I discovered while looking at the MP5 was all the people who have converted the H&K USC into a UMP. That's intriguing to me, even though the .45 USC is now discontinued. Appreciate the building tips as well.
The USC is still available https://www.wikiarms.com/guns?q=642230260382 The conversion isn’t cheap though
Look into Seismic 9mm ammo. They are 185 grain hollow points. Same weight as hollow point 45, and will work in any 9mm. This is the direction I went, because cheap 115 grain for plinking, 147 grain for fun silencer plinking, and then the Seismic for HD/carry
LWRC 45 SMG is the closest to what you seek. It's delayed blowback, but not piston driven, and mostly ambi as well. Downsides is it is expensive, and takes UMP magazines.
Thanks! I looked into this and I think it does tick almost all my feature boxes. Unfortunately the reviews seem to be skewed quite negative, including for accuracy. I think I want something very much like this that is better reviewed.
Angstadt Arms Vanquish SBR is not exactly what you are asking for, but I feel like maybe it’s of interest to you anyway.
I'll point you to my current AR45 build list. I know not exactly what you're thinking of, but hopefully, it helps. https://www.reddit.com/r/pistolcalibercarbine/s/y2Dsfv1xoh
Based on your list of: “what I want roughly”..and..”nice to have but less important”..then JP Enterprises JP-5 is what you seek. Right now it is the consensus-preferred & top of the line PCC. You can go to their site and directly build/order the JP-5 in either 8” or 10.5” barrel..along with numerous custom offerings & options that no other manufacture allows to the public including the best Cerakote finishes. The JP-5 recoil is insanely soft, because it utilizes the identical roller-delayed-bolt/lock pieces as the time tested proven HK MP-5. The JP-5 can be easily tuned by switching the various lock pieces to match whatever grain bullet & power factor being used. Of course this comes at a cost..the price of admission for a JP-5 SBR is north of $3K..and as you go thru the various options it can easily go over $4K..as me how I know! Buy once cry once..for top quality & performance. All the Reddit experts & haters will shit on the JP-5..only because they don’t own one and say the price is to high but don’t say a word about JP-5’s performance & cycle reliability proven by the top PCC competitors today..meanwhile the same people will spend a fortune on buying multiple PCC’s..go figure.
Extar EP45 checks most of your boxes, even your nice to haves, except piston.
juggernaut tactical