[BuckyP]

I'm tossing around getting a 9mm AR. There are a lot of opportunities in my area to shoot a PCC (Pistol Caliber Carbine - as referred to in some competitions), where rifle calibers aren't allowed.

Looking for people's experience with the various offerings. Also, what is the way to go mag wise? I have a lot of G17 mags, including 23 and 33 round magazines. However, if it's better / more reliable to use another mag system, I'm not against buying mags. Basically I'm looking for something that's going to work out of the box without a bunch of tweaking / fussing.

Also, would like to have a good trigger, either stock, or adaptable to some of the aftermarket offerings out there. Do 9mm ARs use the same trigger group as 5.56 ARs?

Appreciate any advice.
:wavey:

 

[Gdirty5]

I have a DDLES 9mm lower, it uses colt SMG mags. Mags can be had for sub 20 dollars, but real colt mags can run you 50. I'm using C-product mags with zero issues. Mine runs like a sewing machine, and the only time I had an issue was when I was using freedom munitions brand ammo, I think it was too weak to reliably cycle the rifle.

For the most part the trigger system is exactly the same, but the shape of the hammer will decide if you can use that trigger group or not. 9mm ar's can get their bolt stuck on the hammer, so best to use one with your standard trigger group that curves backwards. They make ramped and non ramped BCG's so that will determine what hammer it will work with also. I've heard of some people running Geissele SSA's on their 9mm AR.

As far as mags, they make versions that that glock mags and colt mags. I went with colt mags due to aesthetics. I like the straight drop of the mag vs the angle of a glock mag.

The bolt hold open is another issue. Works just fine on my colt version. On the glock version, the angle comes into play. It almost always fails over time on the glock version. I know it's a common issue on QC10, no idea on the lone wolf lower. If that's not an important feature to you, and you want to consolidate mags, then it's still a viable option.

Here's an old pic of my 9mm ar, with 4 inch barrel, 3 lug and suppressed. I have since swapped out the handguards to a seekins MCSR to match my other SBR's

 

[BuckyP]

Wow, fantastic info GDirty5. Bolt hold open is definitely something that would matter to me, as it would come into play in some of the shooting games held in my area.

Do you have a preference for ramped vs. unramped barrels?

Also, I seem to recall one guy (several years back) had a 9mm AR where the brass managed to get into his receiver? Is this a common problem, or has this been alleviated with newer designs.

Again, thank you for your insight.

 

[ronin.45]

Gdirty covered most everything.

I chose glock mags for convenience and reliability. I had a Rock River set up for Colt mags and it was picky on brands. The bolt hold open doesn't matter to me, but I can understand if you want it.
I've not had any issues with brass ejection.
Mine is a Lone Wolf with 5" barrel.

 

[TheDreadnought]

Check out Thureon Defense. One of their rifle styles will accept all those Glock mags you already have.

http://www.bing.com/videos/search?q...&mid=EA379B40F2373E3B755EEA379B40F2373E3B755E

 

[Gdirty5]

Wow, fantastic info GDirty5. Bolt hold open is definitely something that would matter to me, as it would come into play in some of the shooting games held in my area.

Do you have a preference for ramped vs. unramped barrels?

Also, I seem to recall one guy (several years back) had a 9mm AR where the brass managed to get into his receiver? Is this a common problem, or has this been alleviated with newer designs.

Again, thank you for your insight.

I haven't run into that issue. My barrel isn't ramped but my receiver is. It as two ramps that angle into one.

Also there's no gas tube on a 9mm ar Bc it's straight blowback. There's some playing to do with buffers, some use spacers, some use a stack of quarters. Personally I just bought spikes 9mm buffer. Forgot what it's called, like st2x or something like that.

 

[Big Bird]

Buy a SIG MPX

http://www.sigevolution.com/sigmpx

 

[Gdirty5]

Buy a SIG MPX

http://www.sigevolution.com/sigmpx

I will eventually buy the mpx when the K version is available. But at the same time, I'm not sure if you should recommend something so new. There's reports of aftermarket triggers not only locking them up, but also voiding warranty. The charging handle has so much play, that it can cause issues, and the metal on some areas have shown to prematurely wear.

I bought a sig556 when they first came out and a sig716, I learned a lesson from those purchases. Wait until a gen 2 is made. The weight on both of them is just horrible, which they came out with lighter profile versions later. The the fitment of the 556 is just sloppy. The 551's and xi's dont have that issue from my understanding

 

[VCoupe376ci]

I'm tossing around getting a 9mm AR. There are a lot of opportunities in my area to shoot a PCC (Pistol Caliber Carbine - as referred to in some competitions), where rifle calibers aren't allowed.

Looking for people's experience with the various offerings. Also, what is the way to go mag wise? I have a lot of G17 mags, including 23 and 33 round magazines. However, if it's better / more reliable to use another mag system, I'm not against buying mags. Basically I'm looking for something that's going to work out of the box without a bunch of tweaking / fussing.

Also, would like to have a good trigger, either stock, or adaptable to some of the aftermarket offerings out there. Do 9mm ARs use the same trigger group as 5.56 ARs?

Appreciate any advice.
:wavey:

My 9mm AR uses Colt patterned mags. My choice was strictly aesthetic as the angle of the glock mags coming out the bottom looks goofy to me. Whether a standard 5.56 trigger group works depends on the bolt carrier. When using a standard full auto 5.56 carrier, a 9mm specific hammer must be used. With a ramped carrier, a standard AR trigger group works fine. CMMG is the company that produced my complete upper with ramped carrier. I have found the rifle to be picky with aftermerket triggers. Both my Geissele SSA and RRA two stage caused random light strikes and random failures to reset across 4 types of common factory ball ammo. With the factory trigger from the DPMS parts kit the rifle was built from, it has been 100% reliable. YMMV of course.

 

[BuckyP]

My 9mm AR uses Colt patterned mags. My choice was strictly aesthetic as the angle of the glock mags coming out the bottom looks goofy to me. Whether a standard 5.56 trigger group works depends on the bolt carrier. When using a standard full auto 5.56 carrier, a 9mm specific hammer must be used. With a ramped carrier, a standard AR trigger group works fine. CMMG is the company that produced my complete upper with ramped carrier. I have found the rifle to be picky with aftermerket triggers. Both my Geissele SSA and RRA two stage caused random light strikes and random failures to reset across 4 types of common factory ball ammo. With the factory trigger from the DPMS parts kit the rifle was built from, it has been 100% reliable. YMMV of course.

Thanks for the info. Good stuff. :thumbsup:

 

[michael_b]

My 9mm AR uses Colt patterned mags. My choice was strictly aesthetic as the angle of the glock mags coming out the bottom looks goofy to me.

Same here. I wish it didn't, I'd love to reuse my Glock 17 mags since I mostly shoot my 1911's and H&K P30.

I ordered a QC10 colt lower - they are having a sale through today I believe.

 

[VCoupe376ci]

Same here. I wish it didn't, I'd love to reuse my Glock 17 mags since I mostly shoot my 1911's and H&K P30.

I ordered a QC10 colt lower - they are having a sale through today I believe.

Where at? I actually want to pick up a dedicated 9mm lower for a pistol build. The part about it that sucks the most for me is availability to purchase. Nobody local caries either the colt patterned mags or Uzi mags. My local store does have piles of 33 and 17rd glock mags though.

 

[faawrenchbndr]

Colt, CMMG, RRA all make 9mm dedicated lowers. If possible, avoid lowers with the mag well adapter. The Glock mag pattern lowers use some funky receiver parts for magazine retention. I prefer the Uzi pattern lowers. I have a dedicated CMMG 9mm that is quickly approaching 10k rounds fired. Runs like a top. Make sure you get a "ramped bolt" and you can use a standard hammer.

 

[michael_b]

Where at? I actually want to pick up a dedicated 9mm lower for a pistol build. The part about it that sucks the most for me is availability to purchase. Nobody local caries either the colt patterned mags or Uzi mags. My local store does have piles of 33 and 17rd glock mags though.

QC10 has 15% off of their dedicated lowers through their website.

https://www.quartercircle10.com/shop/

PSA Has Colt pattern mags on sale for $26.99 I believe.

http://palmettostatearmory.com/index.php/ar-9-ar-47/psa-9mm-smg-magazine.html

 

[gjk5]

I recently did a QC10/Glock pistol, I was very happy with their product. Just ordered a complete 7.5" upper online and slapped some Magpul junk on the lower, KAK buffer and a SigBrace. It ran great for the couple hundred I have put through it.

 

[michael_b]

I recently did a QC10/Glock pistol, I was very happy with their product. Just ordered a complete 7.5" upper online and slapped some Magpul junk on the lower, KAK buffer and a SigBrace. It ran great for the couple hundred I have put through it.

Did you use a QC barrel or their bolt?

 

[gjk5]

this upper/bcg, the rail on mine is slightly different (but my upper was cheaper)

http://www.ar15upperreceiverparts.com/9mm-pistol-upper-drop-in-kit.aspx

 

[michael_b]

this upper/bcg, the rail on mine is slightly different (but my upper was cheaper)

http://www.ar15upperreceiverparts.com/9mm-pistol-upper-drop-in-kit.aspx

Thanks!

 

[gjk5]

if you are going to do a sig brace pistol, look at the KAK setup, it is a relatively cheap upgrade and really helps the jacked up LOP a standard pistol with sigbrace gives you. Also really locks that sigbrace in.

ETA; if you are doing an SBR, ignore all of that.