AR in 9mm

[rdinak]

I have the urge to build a 9mm AR for a fun plinking gun. Low speed, high drag...nothing fancier than a red dot optic for old eyes to pop tin cans with and teach new shooters.

What collective wisdom can you share?

What brand lower/upper? BCG?

Blocked mag well for the 32 round mags brownells has on sale?

 

[Eastbay]

I've owned 2 bushmaster 9mm carbine 15's. Thought the first one was a lemon, but so was the second. Both brand new and bad experience for me.

 

[SABuzzard]

I went with a CMMG dedicated 9mm lower and CMMG ramped bolt carrier. Runs well with Metal Form 32 round magazines. Gets dirtier than hell with a can on it. I ended up registering it as an SBR and cutting the barrel down to 4 1/2 inches. Whole package is about 24" long even with the suppressor attached. Still get the occasional FTF, but I think it has more to do with keeping it cleaned and well lubed. A little finicky to get tuned up and running.

 

[vaeevictiss]

I put together a Lone Wolf G9 carbine a couple years ago. I ended up SBR'ing it with a 7" barrel and throwing on an SWR Trident.

It takes standard Glock mags so you can use the 33 rounders.

Aside from a misaligned extractor when the guy engraving my lower put it back together, I have had no problems with it and it runs smooth as butter.

I did end up dropping in a timney trigger, and a heavier buffer and spring.

Sent from my SCH-I545 using Tapatalk 4

 

[wfjames22]

I hate it when these threads come around....well at least my checking account hates it!

I've been enamored with pistol caliber sbr's running 5-6" barrels with cans for a long, long time.

 

[800mZero]

I have been pricing out the jp gmr-13.

 

[ORD]

The CMMG 9mm stuff (complete rifles, uppers, lowers, etc.) is all top notch in my experience. They use ramped bolts which means you can use a standard AR-15 hammer instead of the dedicated 9mm hammer, thus reducing the number of "one off" parts you need to worry about. They are also highly reliable with quality mags (i.e. - Colt/Metalform, Brownells, etc...not so much with the ProMag crap).

I have never been a big fan of the Glock mag conversions because I have yet to personally run one that didn't have issues...same with the POS Oly Arms pistol cal carbines. HOWEVER...with that said...I think that JP may have a home run with their GMR-12 9mm carbine offering. I have not seen nor have I fired one yet, but I wholeheartedly trust that anything JP puts out with their name on it will be a success. Their complete ARs and uppers are just simply some of the finest available, but as a result of their name and reputation...you are going to pay for it! Complete rifles setup in the fashion most will want are running $2k+. They also have their (now) older JP-9, Colt-pattern rifles/uppers. In fact, they have a JP-9 upper (just the upper, with magwell conversion block and a 32rnd mag, 9mm LULA, and a 9mm CAR buffer) available right now on their site for ~$1k...that'd be money well-spent!

The RRA stuff used to be fairly good, but I have seen and heard nightmarish tales since they switched over to their "dedicated" 9mm lower receivers several years back. If you can source an older, mag block design RRA, then its a good bet. Be advised though...none of the RRA rifles/uppers/etc. include the ramped bolt I referenced above so a 9mm hammer IS REQUIRED.

If you end up getting a rifle (or upper) with a non-ramped bolt...there are companies that will do a conversion for you fairly cheaply and its worthwhile to have that done. If you are buying/building from the ground up...get the CMMG bolt right out of the gate.

ETA: Almost forgot...Spike's 9mm platform stuff from complete rifles, uppers and individual parts are also excellent in every respect.

 

[SeaBassHWD]

Double Diamond Law Enforcement Supply has a dedicated Glock lower that works with Colt style uppers. It has great reviews. If you already own a 9mm Glock, you should consider this.

 

[wakajawaka]

Can't go wrong with Colt. I've a complete carbine and a short barred upper to use on a pistol lower or my 614.
Get a CMMG ramped bolt or have M60Joe machine one for you.
I converted several Uzi mags back when you couldn't get Colts. They work well but don't hold the bolt back when empty. No reason to do that now unless you have some and like to tinker.
The mag adapter on the pistol lower has a hex screw in the bottom that spreds two pins, locking it in place. It works fine but I won't use it in the 614 as they are rumored to maybe, possibly, crack a lower. Never seen it but ain't gonna chance it.
I really like the looks of the Hahn Precision mag well adapter and would like to have one some day.
I'd stick to Colt or Colt pattern.

 

[KP '14]

I'd go with Double Diamond glock lowers and never look back. That's what my current build is based off of. I own glocks and picked up the 33rd mags, so it just made sense to go with this lower. The glock mags are obviously super reliable too

 

[ZombieMonkey]

The DDLES lowers are the way to go, just keep in mind that for glock mags to properly function the bolt needs to be sent out for machining. I have not seen any of them with issues on these setups. The local SOT has one as a demo gun that is used and abused at demo shoots full auto suppressed. Runs like a raped ape.

 

[mscott]

How about the Just Right Carbine? It takes Glock mags and uses standard AR parts such as triggers, grips, butt stocks, and handguards, so it can be whatever you want.

 

[Oakflat]

Tag for the near future. I already have the 32 round Metalform mags. Just need something to put them in.

 

[WyoWindCall]

In a matter of hours I will be finishing my 9mm ar build. I am waiting on the fortis rail to be delivered. I researched for MONTHS after I bought the CMMG lower back in February. I decided I needed a 1/10 twist barrel because I want to be able to stabilize the heavier 147 grain bullets. I also discovered I needed a ramped bolt so again CMMG was the bolt of choice. I finally just decided it was cheaper to buy the CMMG upper and customize from there. I built the lower up and put a spikes enhanced LPK in it and then hand stoned all the trigger surfaces for one nice crisp 4lb trigger pull. Have a Vltor stock on it and It will have a heavy car buffer spring and for now just a RRA 9mm buffer but that might be upgraded as well. once I get it all assembled Ill be sure to post pics of it tonight/tomorrow.

 

[wildfowler]

My 9mm ar15 is my truck gun. Goes with me everywhere.

Mine started life as a RRA 16 inch upper receiver but now sports a 9 inch tros 3-lug barrel, swr octane 9 can, rra mag block, CMMG ramped bolt, Metalform/ brownell mags. Aimpoint.

I can dump a full mag into a tennisball or less sized group at 50 yds, almost with my eyes closed.

This is my favorite shooter of them all. It's also a very capable and effective Vermin control on just about anything you can shoot at within 100 yards or less.

 

[desertfox01]

Can't go wrong with Colt. I've a complete carbine and a short barred upper to use on a pistol lower or my 614.
Get a CMMG ramped bolt or have M60Joe machine one for you.
I converted several Uzi mags back when you couldn't get Colts. They work well but don't hold the bolt back when empty. No reason to do that now unless you have some and like to tinker.
The mag adapter on the pistol lower has a hex screw in the bottom that spreds two pins, locking it in place. It works fine but I won't use it in the 614 as they are rumored to maybe, possibly, crack a lower. Never seen it but ain't gonna chance it.

I have one of those blocks, never had a problem with it. Actually I really like is because it lets you adjust the block position for the mags. My modified uzi mags sit a little differently then my Colt mags, so it is set for using the Colt mags. If your using a block, the lower can be any mil-spec lower. I did end up using a ASA side charging 9mm upper when I rebuild my a few years back. it is on my SBR lower, with a integrally suppressed 9mm setup.

 

[wakajawaka]

I have one of those blocks, never had a problem with it. Actually I really like is because it lets you adjust the block position for the mags. My modified uzi mags sit a little differently then my Colt mags, so it is set for using the Colt mags. If your using a block, the lower can be any mil-spec lower. I did end up using a ASA side charging 9mm upper when I rebuild my a few years back. it is on my SBR lower, with a integrally suppressed 9mm setup.

Don't get me wrong. I like the mag block a lot. It works very well.
Cracked lowers are probably just internet lore.
BUT, not gonna put in my registered machine gun lower.

 

[window2time]

I love my JP GMR-12 in 9mm. I have several hundred rounds through it and it works great. I have it setup similarly to my JP AR15 and I find that the 9mm is a great way for me to practice for Practical Rifle and 3 gun. It is less expensive to practice with and I can shoot it in the action bays at my local range where centerfire rifle cartridges are not allowed.

I think that pistol caliber carbines are great but in my opinion until the JP was released, the only way to get a high quality PCC was to build it yourself as many have done. JP finally has given us an off the shelf PCC that runs great and is accurate. And of course it runs all my glock magazines that I use in my glock open pistol. I am very happy with it.

 

[WyoWindCall]

Well here she is, she is shooting very well, very accurate, I am having some double feeding issues but I think it is the buffer/spring combo, Im going to the range with a few different springs and buffer weights to get to the bottom of it. Have about 300 rounds through it and had about 15 feeding issues.

 

[grkmec]

I love my JP GMR-12 in 9mm. I have several hundred rounds through it and it works great. I have it setup similarly to my JP AR15 and I find that the 9mm is a great way for me to practice for Practical Rifle and 3 gun. It is less expensive to practice with and I can shoot it in the action bays at my local range where centerfire rifle cartridges are not allowed.

I think that pistol caliber carbines are great but in my opinion until the JP was released, the only way to get a high quality PCC was to build it yourself as many have done. JP finally has given us an off the shelf PCC that runs great and is accurate. And of course it runs all my glock magazines that I use in my glock open pistol. I am very happy with it.

Can you modify an existing lower to take the glock 9mm mags? Or is the lower a proprietary one from JP?

 

[3GunRunner]

Can you modify an existing lower to take the glock 9mm mags? Or is the lower a proprietary one from JP?

Proprietary lower

 

[bullseye13]

View attachment 18652

Well here she is, she is shooting very well, very accurate, I am having some double feeding issues but I think it is the buffer/spring combo, Im going to the range with a few different springs and buffer weights to get to the bottom of it. Have about 300 rounds through it and had about 15 feeding issues.

Me likey! Nice rig.

 

[jonaddis84]

I'm a big fan of the CMMG stuff, mainly just their sub caliber conversion stuff. This guy is basically all CMMG parts except the barrel which is a JSE surplus 7.5" stainless. Dedicated CMMG lower, CMMG 9mm upper, CMMG bolt, YHM Wraith XL. I made an 11.5oz buffer for it to keep the cyclic down, still gets super dirty though with the can. The thing runs flawlessly on subsonic 124gn handloads. I probably have 2k rounds full auto on it and maybe one or two stovepipes that were likely the ammos fault.

https://www.youtube.com/watch?v=wsF2GGb4srg&feature=youtube_gdata_player

https://www.youtube.com/watch?v=avw0uLzDE3k&feature=youtube_gdata_player

Galaxy S3 on tapatalk

 

[MarinePMI]

Been kicking around the idea of one of these for the wife. Low recoil, cheap to shoot and compact enough for the smaller stature shooter...

Just bought another .308, but this project (due to this thread) I think just got bumped up on the list!