PCC AR's, what to look for in a lower?

sam4886

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In the endless cycle of wanting more guns, I'm thinking a PCC would be fun. I want to build one on an AR platform, not buy one of the cool, but expensive, scorpions or stribogs or whatever.

I'm thinking 9mm is plenty for power, easier, and way cheaper to blast through than 45, so I'm primarily looking at the 9mm versions.

I would really prefer that the lower work with any "mil-spec" upper, mainly because I'm a side charge whore and that makes piecing shit together easier.

I'm seeing colt and glock magwells, what is the best option? Seems to me that glocks are everywhere and have more options for extensions, etc. What would be the benefit of going with one of the other mag options?

What about other features? LRBHO? I like the little things like threaded detent holes and stuff.

Any proprietary nonsense to stay away from besides the ejector and magazine release? Some of them have feed ramps buil into the lower, are those only going to work with certain uppers? Are they even needed?

What about brand suggestions? QC10 looks promising. I guess aero is supposed to be releasing one too. How about good ol PSA? I'm open to anything, really. I just want something that's going to work.
 

CrabsandFootball

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Find a quality MP5. HK, Zenith, MKE, POF, Dakota or even PTR. It is the pinnacle of PCC and no one has made a better moustrap yet.

PCC Ar's are always a shitshow and you end up throwing good money after bad.

Even the "top" ones on the market have serious issues. The AR as versatile as it is, is a poor pistol caliber platform.
 

TonyTheTiger

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@sam4886 9mm is where all the PCC development is happening, so it's where parts availability and the reliability is.

Most lowers will work with a standard upper.
Colt mag lowers are dead, Glock is where it's at, and the aftermarket knows this. If you hate your fingers get Colt mags.

LRBHO is literally the first thing you get rid of when you fine tune a PCC. The bolt catches have a tendency to break also.

QC10 or New Frontier Armory are making most of the common/reliable lowers with someone else's name on them, and a lot of the brands making their own pretty much copied them.

JP is great too, and probably the most reliable out of the box PCC you can buy. They're coming out with a MP5-esque roller delayed blowback soon too.

Whatever PCC you end up with, make sure you shoot some matches with it. It's cheap, almost the most fun you can have with your pants on and you'll learn real quick what does and doesn't work. Little local matches like the one below only take a chunk of your saturday morning and are super low pressure.

 

Old Man with Gun

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I have 2 QC10 and love them both. Not all triggers and buffers work with PCC so watch that. I'll post the specs on these when I get home to my notes.

CMMG has a delayed action that is probably safer than straight blow back. I built mine before those options existed.

Not all triggers and buffers work in PCC. Avoid bump stocks as they can cause out of battery detonations.
 

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sam4886

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I dig it. I love my gibbz side charge. From what I'm seeing all you have to do with the cmmg is chop up the fake gas key a bit and it'll all work fine.

Anyone else have any input on lowers? Looks like the JP lowers are like $500. Lol. Qc10 and NFA are probably best, yeah?

I see the qc10 has lots of models, anyone know a quick rundown on what they all mean? Ranger, rider, raider, whatever they're all called....
 

slambeach

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I have two built on 15 lowers w/mag well blocks, and one on a dedicated 9mm lower. All are colt pattern, built before glock pattern were around. They all run fine now, but I did have initial issues with magazines and buffers. The only reliable mags were Mec-Gar's,or factory Colt (made by Mec-Gar) Buy a quality aluminum mag well block, (the cheaper plastic ones have locating tabs that break off after a while),a dedicated 9mm buffer (the front collar is longer, and shim the buffer travel to take the beating off your bolt release. And make sure your barrel has a generous, smooth feed ramp (I had one barrel with just a rough chamfer). If I was building a new one, I'd check into the Glock pattern, mags are cheaper/more available than the good Colt mags. Or you can just Buy an MPX, I love mine! All just my opinion, hope it helps.
 

Old Man with Gun

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Here are my builds:
QC10 lower- Glock, B5 Sopmod stock, blitzkrieg hydraulic buffer, ALG ACT trigger, Gibbz side cocker upper, QC10 bolt-Glock, 5" Tros 3-lug 1:10 barrel, Seekins MCSR v2 10" handguard and SiCo Octane 9 suppressor.

QC10 lower- Glock, MVB ARC stock, MVB 9mm buffer, ALG ACT trigger, Gibbz side cocker upper, QC10 bolt-Glock, 5" Tros 3-lug 1:10 barrel, YHM 4.25" KR-7 handguard and SiCo Omega9k suppressor.
 

Strykervet

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    There are so many and lots of cheap options, it was hard to wade through.

    I wound up going with JP guts (barrel, bolt and buffer assy.) along with a Colt 2 piece pin in adapter and a Colt 9mm upper.

    JP has been backordered since like November though. With no idea when the shit will be here. If it weren't for the fact I already have the mags and I get a discount with 'em, I'd just cancel the order and get the Stribog. I'm gonna die of old age before some of these places get their shit together.

    They're still taking orders though so I guess JP is fine with having backlogs out to a year plus with zero knowledge or even a guess of when they plan on filling 'em.
     

    Strykervet

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    Oh, I have a Tavor in 9mm that uses the Colt mags and it's a bad motherfucker. Dependable, accurate, fast and basically no recoil. 17"bbl. bullpup is same size as a 11.5"SBR collapsed. I actually use it for HD. Almost like shooting a .22 but it hits a lot fucking harder.

    So if any of you have a Tavor, that's a good one to do up in 9mm for a relatively decent price AND it uses the same Colt mags as the AR.
     

    Neurotic

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    Since it wasn't mentioned, I think most pistol mag based lowers put the magazine a touch high for the CMMG RDB. I see people removing mag catch material to lower the magazine to make it work. Don't know how that flys with lowers having LRBHO.

    FWIW, I have a foxtrot Mike that's pretty good for the money. It runs better with the heavier (45acp) buffer, but has bent a (proprietary) bolt catch after 1,500ish rounds; FM sent a replacement free of charge. With a red dot, cheap S&B ammo and the crappy mil-spec trigger it shoots 3-4 moa at 100 yards.
     

    308pirate

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  • Apr 25, 2017
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    In the endless cycle of wanting more guns, I'm thinking a PCC would be fun. I want to build one on an AR platform, not buy one of the cool, but expensive, scorpions or stribogs or whatever.

    I'm thinking 9mm is plenty for power, easier, and way cheaper to blast through than 45, so I'm primarily looking at the 9mm versions.

    I would really prefer that the lower work with any "mil-spec" upper, mainly because I'm a side charge whore and that makes piecing shit together easier.

    I'm seeing colt and glock magwells, what is the best option? Seems to me that glocks are everywhere and have more options for extensions, etc. What would be the benefit of going with one of the other mag options?

    What about other features? LRBHO? I like the little things like threaded detent holes and stuff.

    Any proprietary nonsense to stay away from besides the ejector and magazine release? Some of them have feed ramps buil into the lower, are those only going to work with certain uppers? Are they even needed?

    What about brand suggestions? QC10 looks promising. I guess aero is supposed to be releasing one too. How about good ol PSA? I'm open to anything, really. I just want something that's going to work.

    I would start by searching for your answers and reading what pops up here: https://forums.brianenos.com/forum/318-pistol-caliber-carbine/

    There isn't a group of shooters in this country with more PCC experience than those who use them to compete. They put more rounds downrange through them in a month than most users do in a year.

    Having said that, I can't think of a worse time in history to invest in a 9 mm bullet hose than right now...………:ROFLMAO:
     
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    TonyTheTiger

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    I would start by searching for your answers and reading what pops up here: https://forums.brianenos.com/forum/318-pistol-caliber-carbine/

    There isn't a group of shooters in this country with more PCC experience than those who use them to compete. They put more rounds downrange through them in a month than most users do in a year.
    BE has a ridiculous amount of PCC knowledge for sure.
    Seems like most of the guys on there that tried the CMMG RDB system gave up on them, too many gremlins if I remember correctly.
     

    sam4886

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    I would start by searching for your answers and reading what pops up here: https://forums.brianenos.com/forum/318-pistol-caliber-carbine/

    There isn't a group of shooters in this country with more PCC experience than those who use them to compete. They put more rounds downrange through them in a month than most users do in a year.

    Having said that, I can't think of a worse time in history to invest in a 9 mm bullet hose than right now...………:ROFLMAO:


    I've been creeping around brian enos too.

    I agree that its not an ideal time, but I figure I'll buy a lower before burden tries to ban them and hope 9mm drops back down to reasonable prices. I've been trying to pick up an AK too for the same reasons. I can shoot 7.62 cheaper than 9 right now.
     
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    Winny94

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    In the endless cycle of wanting more guns, I'm thinking a PCC would be fun. I want to build one on an AR platform, not buy one of the cool, but expensive, scorpions or stribogs or whatever.

    I'm thinking 9mm is plenty for power, easier, and way cheaper to blast through than 45, so I'm primarily looking at the 9mm versions.

    I would really prefer that the lower work with any "mil-spec" upper, mainly because I'm a side charge whore and that makes piecing shit together easier.

    I'm seeing colt and glock magwells, what is the best option? Seems to me that glocks are everywhere and have more options for extensions, etc. What would be the benefit of going with one of the other mag options?

    What about other features? LRBHO? I like the little things like threaded detent holes and stuff.

    Any proprietary nonsense to stay away from besides the ejector and magazine release? Some of them have feed ramps buil into the lower, are those only going to work with certain uppers? Are they even needed?

    What about brand suggestions? QC10 looks promising. I guess aero is supposed to be releasing one too. How about good ol PSA? I'm open to anything, really. I just want something that's going to work.
    Aero is releasing theirs on march 3rd. If you can get one, that'll be one you want.
     

    TonyTheTiger

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    Aero is releasing theirs on march 3rd. If you can get one, that'll be one you want.
    But why though? I've heard a lot of talk about it being better than sliced bread but there doesn't seem to be anything special about it. If it's typical Aero it'll be a solid product at a reasonable price, but not a game changer.
     

    Winny94

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    But why though? I've heard a lot of talk about it being better than sliced bread but there doesn't seem to be anything special about it. If it's typical Aero it'll be a solid product at a reasonable price, but not a game changer.
    Thats exactly why - it will just work and be affordable. Not everything needs to be a game changer - doing things the right way with all the wanted features (Glock mag and LRBHO) is plenty.
     
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    TonyTheTiger

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    Thats exactly why - it will just work and be affordable. Not everything needs to be a game changer - doing things the right way with all the wanted features (Glock mag and LRBHO) is plenty.
    Fair enough. I expect it to be good, but I've heard it described as the second coming of Christ with no explanation as to why..
     

    Middle Man

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    Combo of Colt mag CMMG lower (before the Glock mag lowers were de rigure) and JP BCG with silent capture buffer has been a reliable set up with two different 9mm uppers. Successful running ASC 9mm Colt pattern mags. Lula makes a mag loader/unloader that saves your thumbs from abuse.

    Really shoulda picked up a 9mm Tavor back in the 2017 slumping market :(
     
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    Nailbender

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    I don't pretend to be an expert on what's good and what isn't but I have had a good experience with a standard lower and Endomags from Mean Arms. The lower and the mags can always go back to their previous uses but for now the system works very well.
     

    Bantam1

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    Palmetto State has a new version that takes Scorpion mags. That is interesting and mags are cheap with lot's of options.
     

    akmike47

    Mike Ropenis
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    Foxtrot mike lower spikes pistol upper, faxon barrel. I forget what bolt at the moment. Runs great zero issues
     
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    Steel head

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    Palmetto State has a new version that takes Scorpion mags. That is interesting and mags are cheap with lot's of options.
    That would be interesting!

    I’m use a PSA glock lower.
    I have no complaints at all with it.
    Feed and function have been excellent.
     

    sam4886

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    I saw the aero release date thing. May end up going that direction, if I'm quick enough, because I can't find an NFA or QC10 in stock anywhere. Damn near all my normal ar lowers are aeros.
     

    Frank_Castle

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    I saw the aero release date thing. May end up going that direction, if I'm quick enough, because I can't find an NFA or QC10 in stock anywhere. Damn near all my normal ar lowers are aeros.
    Not sure what the lower will sell for but im sure the say will crash, be sold out quickly. I may go for an Aero lower to replace mine for the BHO feature depending on price.

    Gibbz makes some very nice side charger uppers,lowers.