Dubi ran a USPSA match with this gun today. 140 rounds without a hitch, but reloads are a little rough. Also another participant's rifle suezed up--due to ammo failre, he also shot the last four stages for an additional 108 rounds, then about 40 rounds play time after the match.

Roughly a total of 250 hard rounds today no reliability issues. A rough total of 750 rounds on the mag block conversion.


Color me happy.

lexofer said:

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I really want a PCC.

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Won a Sig MPX this weekend. Once it comes in to my FFL it's on. Going to have the dorky 16" barrel for now though.

I got to shoot the full auto Sig MPX this weekend as well, I liked it a lot.

Mr. Dubi said:

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Went to Champion and fired about 200 rounds through it. It ran without issue a variety of ammo even stuff that hangs up in my M&P. I shot 1" groups with a 4 MOA red dot at 15 yards unsupported.

I think I might just keep this one and build another for Dubi.

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Man that is sweeet. I live in BCS so if you do another build I would love to talk about doing one of these, maybe hang out when you assemble. Would love to have some help w the build. I can pay in cash, beer, or cash and beer. A 9mm AR is so awesome.

I hate you a little bit right now.....

Really congrats.

Our update: I dropped the Rock Island mag block into another, unregistered, lower and built a 16" 9mm upper for it. This set up woks absolutely perfectly in testing and practice, but had a failure to extract: stovepipe with the next round going half into battery during a falling steels match this past weekend.

I need to research a bit more to keep this from happening again. I do not know if it is a magazine issue, as it happened after the fifth shot. Most likely it is ammunition related: I have loaded some soft rounds for this current build so I can run a JPE bolt assembly, carbine buffer and standard carbine recoil spring, while keeping the recoil soft with minimal muzzle rise.

The build, using a Colt mag lower conversion block is about as simple as it gets. There is no gas system, so no indexing the barrel nut. The upper is just the upper, barrel and barrel nut, handguard of your choice.

Action is a 9mm bolt asssembly and buffer system of your choosing-- I have buffers from 1 oz to 5 oz and a variety of recoil springs from worn out (softer) carbine springs, AR 10 and extra power carbine spring. I have taken to switching them to tune the recoil and muzzle rise.

The biggest improvement I have found so far is soft loads. With my first conversion on the SBR lower, I had a couple double fires when test firing, so I switched over to another lower with the milspec FCG.

I love my AR-9 SBR. It's my favorite rifle. Short, maneuverable, tons of fun to shoot, and quiet as well with my Form 1 can.

For a dummy like me that doesn't understand reloading or run matches, what is PCC? I get the gist, (pistol calibers).

So, since there's no gas, is it cheaper to build? Pistol ammo is obviously cheaper and less recoil than carbines ) rifle calibers.

Any PCC info for dummies would be appreciated. Just talk real slow!

Pistol caliber carbine. Definitely not cheaper to build, but not much more expensive. You can really make them short. Mine has a 4.5" barrel. It also shares mags with my Glock. They are fun to shoot, quiet when suppressed, and the mad commonality is a bonus for me.

PCC just stands for Pistol Caliber Carbine, so just a short rifle in a pistol caliber. It is liked for the reason's you mentioned, low recoil and cheap ammo. PCC's recently have gotten much more popular so many more companies are making them than a few years ago but they are still generally more expensive than regular .223 rifles.

USPSA, which is a type of pistol competition, started a division for PCC as well as some 3-Gun matches. It's just fun to shoot them.

So if the barrels are shorter and there isn't gas to deal with, what makes them more expensive?

If you get a lower built for Glock mags, it is more expensive. BCGs are more expensive. You generally need to run a longer, heavier buffer, so that is more expensive.

AgLA06 said:

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So if the barrels are shorter and there isn't gas to deal with, what makes them more expensive?

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economies of scale

maverick2076 said:

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If you get a lower built for Glock mags, it is more expensive. BCGs are more expensive. You generally need to run a longer, heavier buffer, so that is more expensive.

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Don't forget the current high demand. PCC's are all the rage in USPSA and 3gun nation, starting up in IDPA as well as the non-competition market.

What I don't really understand is why all the tuning? is there not a bolt/spring/buffer combo that just runs out of the box? My buddy that does a lot of competitions says the AR PCCs jam quite a bit.

I've done competitions with my Beretta CX4 and it's a blast. I'd like the ability to SBR an AR and build a spare 9mm upper to go with it. But I don't want to do it if I can't swap the upper, spring, buffer, magwell, and be ready to go.

True. And they don't have the big production base for the PCC specific parts that they do for standard AR parts.

The best combo I've found is a standard carbine spring with a 9mm buffer. It works perfectly on my suppressed 9mm, an I suppressed 9mm, and a .45 build.

The tuning is to make them shoot more like a .22. You can run a bunch of heavy components and get decent reliability, but you get a lot of sight upset/bouncing red dot, and at the end of a day it'll wear you out. The recoil of a heavily buffered AR9 is much greater than that if a .223 AR, but not quite as sharp.

I got to shoot the JP dedicated 9mm PCC for the first time after the steel match out at CCC last month and am definitely hooked. I've been coming up with all kinds of reasons why I need one to try to justify the cost to myself...

HUEY04 said:

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I got to shoot the JP dedicated 9mm PCC for the first time after the steel match out at CCC last month and am definitely hooked. I've been coming up with all kinds of reasons why I need one to try to justify the cost to myself...

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That guy was the impetus to go down this road, but I don't think I have even held that JP!

Haha! I've shot it!

Mr. Dubi said:

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Quote:

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Following


Does any 9mm work for that division? Mainly, Scorp Evos?

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Carbine or Registered SBR. No SMG style or AR pistols.

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So I'm assuming an MP5 or MP5 clone is a no go?

Is this basically for AR platform in pistol calibers?

You can shoot any legal pistol caliber carbine. AR9's, Evo's, CX4's, MPX's, MP5 carbine or the like. Those with Sig Braces or Shockwave Blades are not allowed.

USPSA PCC rules

This is Dubi's current PCC. The only parts in this gun from the original build is the handguard.

It is a dedicated Spike's 9mm Colt pattern lower, I got a 16" barrel for it since the lower in not a registered SBR. Everything else is new to this rifle as well, except the buffer tube and its associated parts--they were canibalized off a rifle I had sitting in the safe, and the compensator--it was from a pistol experiment.