Best upper receiver for suppressed AR pistol?

M

Major727

New member
Could someone please recommend the best value for the $ upper for my new suppressed 5.56 AR pistol? Now I am thinking of 11.5" BCM-MK2-URG-11-BFH-MCMR-10 or PSA Sabre 10.5" model 5165490534 PSA 10.5" CHF Carbine Length 5.56 NATO 1:7 Geissele 9.5" MK14 M-Lok Upper - No BCG or CH. Both barrels should be good (DD vs FN), both have overgassing issues when suppressed (I have no clue yet how to deal with it). The intent is to mostly shoot the gun suppressed and in 20% of time unsuppressed in a user friendly way (I am thinking of a Polonium K suppressor). The Aero Precision complete lower is being shipped. I have 0 experience shooting a suppressed rifle - 9mm pistol only and I prefer to stick to 5.56/.223 caliber.
Am I on the right track? Does anyone have better suggestions?
If I had all the money I would like to spend, I would probably just buy a KAC. My objective is to get something that is almost in the upper tier for the mid-tier price. Most importantly, if any weapon fails to eject or the rounds from several decent brands are getting stuck, I am getting rid of it very quickly (e.g., my Beretta Cougar mistake).
 
I would consider some form of gas regulation for either choice.

FWIW...BCM, is currently offering all uppers with a free BCG, under the options section.BCM upper has "dual vents machined at the rear (each side, above charging handle latch) help to redirect and vent gas away the shooters face"

BCM also sells a Charging handle designed for gas redirection...The U.S. patents pending BCM Mod 3 Charging Handle now features upper and lower and side exhaust channels to vent gas from the chamber away from the shooter during operation of the weapon.
https://bravocompanyusa.com/bcm-ambidextrous-mk2-charging-handle-medium-latch-5-56mm-223/


Normally I would use a Adj. GB to regulate gas at the barrel end... but this link is a easier way to swap gas flow as needed.

IE, something like this... https://bootleginc.com/product/bootleg-four-position-adjustable-carrier/

I will also mention... while a 10.5" is sexy, sometimes a longer barrel length can give a respectable boost in velocity... ( post # 4 )

https://www.ar15.com/forums/ar-15/Suppressed-5-56-SBR-Velocity-Tests-41-Factory-Loads-from-10-5-11-5-12-5-and-14-5-ALL-DONE-/16-714088/

Please be aware... the amount of gas at the face from suppressed, after 30rds can be a eye opener. ( or better said, an eye burner )

Other options are a BCG optimized for suppressor use.. https://cmctriggers.com/product/cmc-ar15-bolt-carrier-group-suppressor-optimized-milspec-black-nitride-5-56-223/

In as much as I love PSA products... the BCM Mk2 gas "deflection" is making me want to buy one now.
 
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IMO, you might be over thinking things a bit. I've been using an Omega 300 suppressor since 2020 on a 7.5" .300 BLK pistol and 16" Colt AR-15. I really don't notice a lot of gassing back through the upper. As when I'm shooting, I'm outdoors and almost always in some sort of breeze and the gasses are carried away quickly. I might be a little immune to blowback gasses as well, after 21 years of shooting military weapons with blank adapters.

Nothing against your suppressor choice, OCL makes great suppressors. I have a friend that really likes them, and has around six of them. If my main concern was blow back gasses, I'd buy a flow through suppressor.

This coupled a piston upper or some other products mentioned to minimize blow back gassing would be the way I'd go. There are flow through designs on both sides of the Polonium K price point you can consider. Witt Tool Canooter Valve suppressor would be the most affordable and your high end would be something around a HuxWrx suppressor.

Blow back will be more noticeable on any Pistol, PCC or AR in pistol calibers, as that's how they operate. If you're shooting an 5.56 AR pistol like a pistol, then I doubt you'll notice much of the back flow of gasses. As the upper receiver will be further away from your face than shooting an AR rifle where your nose is right at the charging handle.
 
50 shooter said:
Riflespeed adjustable gas block.

https://www.riflespeed.com/RIFLESPEED-Gas-Controls-750_p_12.html

Tubb flatwire spring.

http://www.davidtubb.com/ar15-bufferspring

Odin Works adjustable buffer.

https://www.odinworks.com/Adjustable-Buffer-p/os-abs.htm
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Pretty sure your over thinking it. so a friend of mine has 2 uppers for a SBR, both in 5.56, a 11.5 and a 7in with a Silencerco omega 300. both are running H3 buffers with springco red springs and an Aero precision adjustable gas block on the 11.5 and both still eject at the 1 to 1:30 position with everything tuned.

the 7in is noticeably shorter and more maneuverable. its also noticeably louder with no suppressor. I personally prefer the 11.5in as it runs smoother and is easier on the gun since it has a longer gas system.


Personally I prefer the KAK configurable buffer system, more versatile. only downside is that you have to punch a roll pin to change weights. but you receive 3 light weights, 3 steel weights, and 3 tungsten weights so go from ultra light, to H3 and a few odd combos in the middle, depending on your needs.
https://kakindustry.com/configurable-buffer-kit
 
Thanks... Since I only want 5,.56/223, a compromise to mitigate over gassing may be a longer pistol barrel - up to 14..5 on BCM. Sounds like a lot but with a folding stock may look not too bad. I need tried though. The problem with BCM - 14.5" are also out of stock in my particular configuration (because that's almost everybody wants now, I guess). 12.5" is there too but non-existent in my configurwhat ation at all.
To be fair, today I received and email from BCM today about 11.5" being in stock, I saw it in stock, ran downstairs to get my credit card before putting it in the basket and sure enough - it was sold out again There was probably 15 mins before they sent and email and the item being sold out.
Better production planning would not hurt BCM bottom line.
 
up to 14..5 on BCM. Sounds like a lot but with a folding stock may look not too bad.
Click to expand...

If you put any "stock" on a pistol you could be turning it into an NFA regulated weapon. This is a CRIME, unless you get it registered with the ATF BEFORE you do it.
 
You are correct, 44AMP. Sorry, it will be my 1st AR pistol and I am still getting used to the word "brace". The Aero Precision lower I ordered has a foldable brace - $750 or so for the lower with the brace before I even think about replacing the trigger. I have plenty of 16" AR rifles and probably a 14.5" pistol would not look very different there. Probably 9.5 - 11.5" woul make more sense for me. I wish Aero Precision could offer assembled uppers that have good cold Hammer forged barrels.
 
I highly recommend the JP enhanced reliability spring kit for the trigger. It takes about 2 to 2.5lb off your pull weight and makes mil-spec trigger feel noticeably lighter and less gritty and it reliability sets off hard mil-spec primers. And the best part is its only $10.40

https://www.midwayusa.com/product/1003366096

It does say 3.5lb but thats assuming your mil-spec trigger started at 5.5 to 6lb, in my experience most are a fair bit heavier, in the 7 to 12lb range in my experience.

As far as cold hammer forged barrels, i dont like them. They tend to have point of impact shifts when they get heated up due to the tension in the steel from the hammering. Aero is partnered with ballistic advantage on barrels. Ballistic advantage has a 1moa guarantee on their barrels. Never been dissapointed by a ballistic advantage barrel.
 
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Thanks for the trigger spring advice. I will look into this. I was actually thinking about replacing the Aero Precision trigger with a Geisselle 2 stage trigger - something I did on my YHM 16" 5.56 AR, but I am not sure if the extra expense is justifiable.
I gave BCM several options and used the 1st one in stock - so I just ordered a 14" BCM upper ($1,000 with BCM charging handle, shipping and tax).
Now I am asking myself:
1. Is it worth to hunt for a complete BCM lower and use my Aero Precision pistol lower for my next project instead? Does BCM lower make a difference, pride in displaying BCM logo aside?
2.Is it a good idea to take a chance with a PA, FN barrel, Geissele rail and gas block, "Sabre" CHF 10.5 pistol upper if I run it through post purchase QC with a local gunsmith (I have no idea how much people normally pay for it)?
 
I ordered the recommended JP spring kit. That may be a far better value for $ that buying a fancy Geissele trigger. I think Aero Precision barrels are Ballistic Advantage, hopefully my 6.5 Creedmoore stainless barrel as well. I noticed that the Aero Precision PRO uppers are actually more expensive than BCM. I would still consider it if they had a Magpul Cerakote color option. For now it is only black.
 
I think you will be very happy with the jp spring kit, they make a big difference.

You could also get it cerakoted later. I personally prefer that.
 
You can buy the stuff to do yourself, but i meant that there are lots of gun shops that offer custom cerakote services. So if you cant get the color you want for a build, just buy it plain, and get ot coated later the way you want it. I have a couple shops locally that do it, but im also in a big city. I usually rattle can my own stuff, but i did get a beat up glock slide cerakoted in od green by a shop, came out great.
 
KAK has a down venting bcg that reduces gas and decibels that's worth checking out. And get a flow through can like huxwrx or Rd or cat.
 
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