9mm pcc build

[black5.3]

Hey guys,

I know this will be a “pistol” build but figured it will be almost identical to the AR platform so im hoping it will get more traffic here and i can get some questions answered. I am not well versed on the pcc arena and the last round bolt hold open feature is not on every model and thats what the most of my questions are come from. I am wanting to build a 9mm on cmmg’s radial delayed blowback internals. My understanding is you buy their kit that contains the bcg and barrel because those are patented and work as a system. The rest of the upper is just standard AR upper receiver and hand guard minus gas system parts.... so now where the real questions start, im wanting to run dedicated glock mags since i own a couple glock pistols and this will give me another reason to stock up on more glock mags. Do i still need a lower that is designated as having a last round bolt hold open feature if i do want it to have that feature? If so, is there a brand/model you guys have used and had great luck with that you can recommend for me?

I am not interested in running mag adapters on standard AR lowers or buying conversion kits for pmags to make them run 9mm. I know cmmg sells their lower as well but i wanted to see what you guys have done and recommend. The plan is to also run this gun 100% suppressed with a sick omega 9k that I will be getting the paperwork started on soon. Thanks!

 

[black5.3]

Also forgot to add it will be getting a decent pistol brace to avoid form 1 and also so I can travel freely with it like a handgun/pistol.

 

[ChitownCopper]

Jp enterprises

 

[TonyTheTiger]

Most guys that go balls deep into PCC's short stroke them to speed up cycling and reduce dot bounce, and this eliminates the BHO feature.
Good call on getting a dedicated lower, adapters can be a pain. New Frontier Armory makes a lower that a ton of different companies have their name on, it's got a very good track record.

 

[black5.3]

Jp enterprises

Im aware that with the brand JP Enterprises comes quality and a great track record.... but looking to keep it a little cheaper than what they offer. Thanks anyway and I failed to mention that this will not be a super expensive build.

 

[black5.3]

Most guys that go balls deep into PCC's short stroke them to speed up cycling and reduce dot bounce, and this eliminates the BHO feature.
Good call on getting a dedicated lower, adapters can be a pain. New Frontier Armory makes a lower that a ton of different companies have their name on, it's got a very good track record.

I have seen the New Frontier Armory stuff and they have good reviews. I will look into them further. Thanks.

 

[Steel head]

I use a PSA glock lower for mine.

I’m really enjoying shooting it and it’s been very reliable.
I’m contemplating getting a side charger upper receiver for it.

 

[black5.3]

I use a PSA glock lower for mine.

I’m really enjoying shooting it and it’s been very reliable.
I’m contemplating getting a side charger upper receiver for it.

From my limited research of psa stuff, don’t they require you to use their upper?

 

[Steel head]

From my limited research of psa stuff, don’t they require you to use their upper?

No
I’m actually using an old slick side dpms upper on mine.

I had to do some work on the New Frontier bolt to get it to work.
Deburred the extractor slot and machined the firing pin that had a non colt profile.
They never even answered my emails to them so they won’t be getting any more of my money.

 

[roostercogburn98]

Only regret I have but there wasn’t much choice 9 years ago when I built my sbr 9mm, but use a Glock mag compatible lower. The modified uzi mags work once you figure out the right mag catch cut for your gun but one less thing to worry about.

 

[woodsmoke]

I’m also running the PSA/Glock dedicated lower with a pistol brace. I built the upper with the parts I wanted: slick side receiver, Faxon 4.5” barrel, Spinta bolt. It has functioned flawlessly. Really fun to shoot, super quiet with a can and 147s.

 

[black5.3]

No
I’m actually using an old slick side dpms upper on mine.

I had to do some work on the New Frontier bolt to get it to work.
Deburred the extractor slot and machined the firing pin that had a non colt profile.
They never even answered my emails to them so they won’t be getting any more of my money.

View attachment 7224865

Ok good to know! Was just looking at New Frontier Armory stuff and seems like good quality stuff. Will be looking at more PSA options as well.

 

[black5.3]

Only regret I have but there wasn’t much choice 9 years ago when I built my sbr 9mm, but use a Glock mag compatible lower. The modified uzi mags work once you figure out the right mag catch cut for your gun but one less thing to worry about.

Definitely going with a dedicated glock mag lower.

 

[black5.3]

I’m also running the PSA/Glock dedicated lower with a pistol brace. I built the upper with the parts I wanted: slick side receiver, Faxon 4.5” barrel, Spinta bolt. It has functioned flawlessly. Really fun to shoot, super quiet with a can and 147s.

Im thinking PSA will be a good option for sure. I know their prices are good and for some reason I thought their lowers were picky about the uppers they fit.

 

[MPDS13]

I have a complete CMMG Guard 9 AR pistol that I shot dedicated suppressed with DeadAir Wolf 9SD. I ran a Geissele Super 42 buffer system to slow down the bolt from the suppressor. It ran smooth as hell and was very fast to shoot. The CMMG glock mag lower was really nice especially with the last round hold open. You may want to look into just buying a complete pistol. They will work with you and you can order what you want and they will customize it for you. At the time I ordered the Guard 9 pistol they did not offer it in the configuration I was wanting. My local shop and I called them and they built what I wanted no problem.

 

[black5.3]

I have a complete CMMG Guard 9 AR pistol that I shot dedicated suppressed with DeadAir Wolf 9SD. I ran a Geissele Super 42 buffer system to slow down the bolt from the suppressor. It ran smooth as hell and was very fast to shoot. The CMMG glock mag lower was really nice especially with the last round hold open. You may want to look into just buying a complete pistol. They will work with you and you can order what you want and they will customize it for you. At the time I ordered the Guard 9 pistol they did not offer it in the configuration I was wanting. My local shop and I called them and they built what I wanted no problem.

I have also considered this option, as its easy to point to a gun I want and lay the money down and go shoot. The main reason im looking into building it is so i can be more specific on the small items like trigger, rail, brace and so on. Hopefully catching these items on sale along the way and coming out with a gun that is exactly the way I want and maybe a little cheaper than their production gun. Im looking at basing the build from their stripped lower and that thing is expensive! A lot of guys are saying to use their lower because of the precise mag angle and seating depth alleviates a lot of the feeding and bolt hold open issues.

 

[SharpsNitro]

If I were looking at doing one of these today I would be looking hard at the new Angstadt MDP-9.

 

[black5.3]

Their stuff is quality but you also pay a premium too.

 

[ricard13]

New Frontier Armory has great dedicated glock 9mm lowers with the LRBHO feature. I use their lowers (actually the Joe Bob branded ones) on my 9mm builds. Never had any issues. Sound like you will be going with a cmmg barrel. One thing I will mention is that not all 9mm barrel out there will feed hollow point very well. I know this from personal experience. If I could start all over again I would buy my barrels from Macon Armory. he polishes and opens up the feed cone on the barrel. I had to send all of my barrels to him to have him perform these services, would have been cheaper to just buy barrels from him to begin with. The cmmg barrel kit might not have this issue, but it is something to be aware of.

 

[Mute]

Just some fyi, since you're asking about last round hold back. Many of the pcc competitors run the short stroke setup to speed up their shooting, but usually those will not hold back the bolt after the last round. JP Rifles have a specific short stroke setup for their SCS system and their website states very specifically that that particular setup will not hold open after last round. So if you want to have the bolt lock back, you probably want to avoid using these types of setup.

 

[black5.3]

I do not plan on competing with this build at all. This is going to be a training gun as well as an AR platform to help maybe get my wife motivated to shoot a little more. The last round bolt hold open is important to me so it will be like other semi auto weapons I have and make reloads faster.

 

[davsco]

bolt hold open? bwahahaha. with 40-50+ round mags, extenders and drums, hopefully we can find a place to reload before going dry!

 

[Landon4]

I’m running a dedicated spikes lower with a gibbz side charging upper suppressed, I prefer the side charge it’s easier to use I think. I’ve ran several other upper and lower combos and sometimes the bolt locks back but not always, it doesn’t work on the one I’m running now all the time either, you can mess with it from what I’ve researched but it’s not that big a deal to me.

 

[Steel head]

I’m running a dedicated spikes lower with a gibbz side charging upper suppressed, I prefer the side charge it’s easier to use I think. I’ve ran several other upper and lower combos and sometimes the bolt locks back but not always, it doesn’t work on the one I’m running now all the time either, you can mess with it from what I’ve researched but it’s not that big a deal to me.

pics of the Gibbs?
Does it need bolt mod to operate?

 

[Landon4]

No I’m running a spikes bolt in it, these pics were before my can showed up and it’s wearing a sig red dot now, this is also with an 8” barrel and slr comp

 

[black5.3]

Man i plan on running glock 17 mags and glock 33 round mags because thats what i have plenty of. Im not real interested in buying expensive drums and whatnot.

On a side note, I have been doing a lot of googling on the topic of building a pcc on cmmg’s radial delayed bcg and barrel. There is a pretty lengthy thread on arfcom(I know, arfcom)and they are saying to build a pcc that 100% feeds, ejects, and functions normally without a lot of mods and tuning then you need to build off their redial delayed system using their upper and lower receivers... on cmmg’s website, im seeing the stripped lower for $375, redial delayed blowback barrel and bcg for $350, and then the upper receiver for $140.. just those put me knocking on the door of $1,000... by the time i put a decent trigger, lower parts kit, and SB brace it would probably be about the same price if not a little more than just buying their factory gun..... That proprietary lower receiver for $375 kinda pits a dent in things.

 

[Landon4]

Man i plan on running glock 17 mags and glock 33 round mags because thats what i have plenty of. Im not real interested in buying expensive drums and whatnot.

On a side note, I have been doing a lot of googling on the topic of building a pcc on cmmg’s radial delayed bcg and barrel. There is a pretty lengthy thread on arfcom(I know, arfcom)and they are saying to build a pcc that 100% feeds, ejects, and functions normally without a lot of mods and tuning then you need to build off their redial delayed system using their upper and lower receivers... on cmmg’s website, im seeing the stripped lower for $375, redial delayed blowback barrel and bcg for $350, and then the upper receiver for $140.. just those put me knocking on the door of $1,000... by the time i put a decent trigger, lower parts kit, and SB brace it would probably be about the same price if not a little more than just buying their factory gun..... That proprietary lower receiver for $375 kinda pits a dent in things.

When I first shot my 9 above in the pics it didn’t cycle to well I lubed up the bcg fairly heavy loaded up 3 mags and handed it to my 13 year old son and said knock em out, it cycled every round no issue after that I cleaned it up, and have put probably close to 500 more rounds thru it without issue

 

[black5.3]

When I first shot my 9 above in the pics it didn’t cycle to well I lubed up the bcg fairly heavy loaded up 3 mags and handed it to my 13 year old son and said knock em out, it cycled every round no issue after that I cleaned it up, and have put probably close to 500 more rounds thru it without issue

I take it your gun is just blowback operated?

its my understanding with cmmg’s setup that the bolt rides at a different height or something is different than just a standard blowback operated system which causes it to need a slightly different mag angle to feed properly. The ejector is also built into the bolt just like regular AR platform which supposedly can cause it to be a little more picky about ejection for size and bcg velocity when firing.

 

[Landon4]

Yes just standard blowback, I’m not familiar with the cmmg design

 

[everready073]

I have heard good things about the foxtrot Mike Lowers. Primary arms, Brownells, and AIM Surplus run sales on them

 

[black5.3]

Thanks, i will look into them as well.

 

[Strykervet]

I'm gonna ignore your AR request and give you a few other options to check out for variety. 9mm AR's just don't seem to be the best DIY options IMO and there are lots of factory built versions for fairly decent prices given the quality.

Seriously, you want a good and cheap 9mm? Check out the Stribog, I think it's the A3 they recommend? The one below appears to be an A1. Anyway, when AMU did their 9mm test, the Stribog actually tested just under the BT they went with. It's also a $500 weapon. Dillon did a write up on it last year, meant to keep that one. Apparently this is a $500 9mm rifle you can bet your life on and I fully intend on getting one some day, probably soon. This one looks kind cool but the earlier more basic ones are bit fuglier. IMO, this is a must have for most folks if prices stay low.

Besides, you really want another AR? And if that's the case, just go .300BLK, same size, length, cost and way more firepower. For serious shit this is the way I went. I'd feel a lot more comfortable in a shitty situation with one too.

I went Kriss Super V, it's about as far from an AR as it gets. Lots of fun, a little costly and hard to recommend due to weight and funky ergonomics but it's the only weapon I've ever fired that doesn't recoil, it fucking vibrates (?). Super accurate and it just dumps all the rounds into the same spot with no effort. But at 8+lbs. and a proprietary recoil system, it better. Not what you're looking for, just throwing out some options for 'ya since I recently went down this road. Upside to Kriss is Glock mags and it can be converted to other calibers (I understand they're supposed to be coming out with a new version of this weapon that uses rifle cartridges, can't wait to check that out and I hope they unfuck some of the ergo issues --I think the mfg. just needs a grunt on the design team).

FWIW, almost went with EVO3 but mfg. neglected to include info about removal of the fake can or what size cans would fit --would've bought it otherwise. If you own an Osprey can though, you owe it to yourself to get one of these, it was made for it. It fits other cans too, wish I'd known. It's a really nice rifle with huge oversize controls that are well placed.

Considered a Copperhead but Sig in their infinite wisdom made the goddamn thing with a permanently attached brake thing (it's 9mm, it needs threads or nothing!).

Since none of these are full auto anyway, I'd go light and compact for a serious weapon and if you own Glocks, well, Glock mags are a good way to go and the 33's are on sale right now at Brownells.

A little inspiration on the non-AR side of things, it's fugly but fun and get's it done. First one is folded with 33rd. mag, second is open with 17rd. mag. I keep the 17rd mag in it mostly but a dozen 33's "just in case", I do wonder how a beta mag would work though...

But WHATEVER you get, consider the Tailhook for a brace if you don't Form1. For a minimalist setup it can't be beat. All aluminum, no rubber or velcro. Super light. Highly recommend the Omega 9k for a can if you don't have one, works on pistols, rifles, whatever, and uses all sorts of mounts. I don't like multi use cans but I do like this one and it's ability to pretty much fit anything 9mm or .300BLK. It's also short and very effective and something you may wanna consider for your 9mm later since they suppress so well.

Good luck whichever way you go. Hope my options here help give you ideas.

 

[black5.3]

You gave a lot of great info and I appreciate you taking the time to do so! The Stribog has also been heavily considered due to the price and rave reviews but what kinda turned me away from it was the “newness” of the brand here in the US and not much aftermarket support for it(yet). I already run a 8” 300blk(it was what I originally built and registered my sbr lower for). So the 9mm pcc is kinka feeling a void of what i dont have, and i admit, im being kinda picky about its requirements. Im not looking to cheap out, i fully understand if i build this how im wanting to it will easily cost 1k-$1,200. I guess we will see if any new developments happen at shot show... supposedly Stribog either has a delayed blowback setup in the works or its already out and just not being exported to the US yet. We will see.. Also, the omega 9k paperwork should be submitted hopefully in about 2-3 weeks.

 

[Mute]

Truthfully, were I not stuck in CA, I'd probably go with a non AR platform for 9mm.

 

[Downtown]

I've not tried one, but I believe the CMMG uses a delayed blowback system. It has a rotating bolt that has beveled lugs that unlock after a delay. Seems like a good idea and I'm curious to hear from someone if it works. Might be ideal for .45ACP, which can be a little violent with straight blowback.

 

[black5.3]

The cmmg radial delayed blowback system is what im wanting to build off of. Thats why i started the thread to see who has built off of the cmmg system and get specific info on what parts(upper/lower)was used.

 

[Downtown]

Sorry, black, I went back and read your original post and that's exactly what you're asking. Guess I got distracted by all the other posts. Well, I'm watching this too, now. I've two Circle 10 Glock lowers I've been meaning to build on. You ve got me thinking CMMG now.

 

[Mute]

When it comes to AR's and especially these 9mm blowback ones, if you choose to run a non-standard system, it's usually best to use as many of the components of the system as possible so you don't waste time or money trying to get everything to play nicely together. It's usually when you mix and match things that you run into hiccups and wind up spending more money to fix the issues.

 

[Landon4]

That’s how I would look at it also, these parts were designed to work together for a reason

 

[black5.3]

Thats kind of what it’s starting to sound like.. unless i can get some real experience from others in this thread to sway my thinking so far it seems like you need the “builder kit” cmmg sells which is just their barrel and bcg. And for proper feeding from glock mags and last round bolt hold open feature you need to run their lower. Next i have read guys using just about any standard upper but some are having issues with the brass ejecting and hanging up in the ejection port. So some people are running .458 socom uppers because of its bigger ejection port.

 

[Landon4]

My gibbz has an enlarged ejection port, it’s a pcc upper

 

[black5.3]

True, there are plenty of pcc uppers with the widened and beveled ejection ports. For people wanting the bigger ejection port and retaining a dust cover, the 458 socom upper seems to be the cheapest “easy” option. Also you get the forward assist as well.

 

[Landon4]

Does the cmmg bolt have the serrations for the forward assist I’m pretty sure my spikes doesn’t

 

[black5.3]

Yeah it does im pretty sure... looks like a standard AR bcg.. even has the ejector in the bolt face.

 

[Screwball48]

I have had a Black Creek Precision lower siting in the box for a while now. Like you I have been planning to build a CMMG RDB upper to go on it. Then I stumbled on a used PSA upper. So far I have only fired a single magazine through the gun, but it left me with a grin on my face.

 

[black5.3]

I have had a Black Creek Precision lower siting in the box for a while now. Like you I have been planning to build a CMMG RDB upper to go on it. Then I stumbled on a used PSA upper. So far I have only fired a single magazine through the gun, but it left me with a grin on my face.

So what is the details on your build?

 

[Screwball48]

So what is the details on your build?

BCP lower, Daniel Defense LPK, KAK shockwave blade, PSA 10.5" upper gen4, and compact ACOG. As it sits now it is a mut with parts scavenged from here and there. Decidedly not complete, but functioning.

 

[Strykervet]

You gave a lot of great info and I appreciate you taking the time to do so! The Stribog has also been heavily considered due to the price and rave reviews but what kinda turned me away from it was the “newness” of the brand here in the US and not much aftermarket support for it(yet). I already run a 8” 300blk(it was what I originally built and registered my sbr lower for). So the 9mm pcc is kinka feeling a void of what i dont have, and i admit, im being kinda picky about its requirements. Im not looking to cheap out, i fully understand if i build this how im wanting to it will easily cost 1k-$1,200. I guess we will see if any new developments happen at shot show... supposedly Stribog either has a delayed blowback setup in the works or its already out and just not being exported to the US yet. We will see.. Also, the omega 9k paperwork should be submitted hopefully in about 2-3 weeks.

I totally get it --I wanted a 9mm but didn't want another AR since I've got several and still have four receivers that need fleshing out. I'm done with AR's after this, I swear. So that's why the Kriss and the other ideas. Working up the nerve to pull the trigger on a 1919 kit. Oh, saw belt fed uppers on gunstroker, 9mm belt fed uppers at that.

I still think Stribog is a such a good deal that I'll probably get one or another in the future. I think that delayed blowback is the feature I heard mentioned regarding a Stribog in a rifle caliber. I looked at the BT APC 9k --the other one I want? The one the army went with? Yeah, $2500 and I'd still need mags and glass. For a 9mm. Or .45.

Good luck on the 9mm build and if you want I started some threads awhile back about 9mm builds that had some good info. Especiallly about lowers, which work best, about converting standard lowers and what is best, Glock lowers and which uppers work best with which lowers. There's a lot of info on here though.

Oh, you're gonna LOVE that 9k! The ASR mount is the shit for carbines if you want a flash hider QD mount.

 

[black5.3]

Man thanks again! Excited to get something going but still have a lot of research to do... while I haven’t given up on the idea of the cmmg rdb setup. Im still keeping my eye out for stribogs release of their radial delayed blowback as well. Well its already released but waiting to see if it will be imported to is any time soon.

 

[MDFMFG]

Aero Precision just released a PCC Receiver. I have been holding out for theirs so I am excited to give it a try.