9mm AR

[Cetmeman]

Just bought an RRA 9mm Mid length upper. I plan on pairing this with a dedicated lower. Have been looking at the CMMG lowers but don't know that much about the 9mm ar rifle. My main concern is the mags and which fit without and mods to them. Has anyone ever used one of these and which mags do you use in them. Says they use uzi mags and colts. I really want to use the C- products or maybe a promag. Any thoughts, thanks.

 

[wreckdiver]

I have a Colt 6450 9mm AR. The factory Colt mags are the best, but the c-products mags function just fine.

 

[erwos]

The C-Products site claims that their mags work fine in an RRA setup if you lower the magwell block by .015-.020. Might be helpful to pick up some 9mm snap caps to experiment with if you're going that route.

 

[JWLaRue]

...since your are going with a dedicated lower, why not the RRA dedicated 9mm lower?

-Jeff

 

[Jimmmy1111]

I use a Hahn top load block with a RRA long finger bolt catch. Mags modified uzi and metalform colt. C products will not run in my RRA or colt pinned block 9mm

 

[boatbiologist]

another for C-Products 9mm AR mags.

Have several 20 and 32, some still in the wrapper. Of the 10 I have tried, none made it thru the entire mag without a failure using a RRA block. Shot all types of ammo, been thru 3 different buffers and springs, 2 triggers, tweaked the RRA block up and down, polished the chamber and bolt and had the trigger worked on. I keep hoping they will break in and start behaving.

Gotta get some metaform mags from CDNN before they are gone.

If you want some new C-Products mags, I'll make you a deal

 

[JWLaRue]

Yup, those kinds of problems with a magwell block is what convinced me to go with the integral RRA 9mm lower.

-Jeff

 

[K-Romulus]

another for C-Products 9mm AR mags.

Have several 20 and 32, some still in the wrapper. Of the 10 I have tried, none made it thru the entire mag without a failure using a RRA block. Shot all types of ammo, been thru 3 different buffers and springs, 2 triggers, tweaked the RRA block up and down, polished the chamber and bolt and had the trigger worked on. I keep hoping they will break in and start behaving.

Gotta get some metaform mags from CDNN before they are gone.

If you want some new C-Products mags, I'll make you a deal

What helped me was tweaking the ejector a bit . . . I found some instructions at the AR15.com "Pistol Caliber AR" forum.
(I use a Hahn bottom-loading mag block.)

Basically you use some pliers to CAREFULLY bend/tilt the whole exposed ejector on the mag block towards the direction of the inner bolt face until it LIGHTLY started to drag on the bolt. If the ejector is off by 0.001" or something, the whole Colt system will fail to work (with C-Products mags, especially, in my experience) as far as ejecting properly.

My main C-Products mag issue was failure to eject, with the empty case getting stuck above the chamber as a live round was trying to feed. Once I tweaked the ejector, it seemed to clear things up.

ETA: one other issue is that the front of the C-Products follower would hang up at the bottom of the Hahn feed ramp. That would prevent the entire follower from rising, and so it would not activate the bolt catch. Some sandpaper for 10 secs to round off the front corner of the follower fixed that.

But I agree, I never had that problem with my 90's era Colt mags (same specs as the Metalform).

Whenever I make it to the next MDS Shoot I will bring everything with me to show people.

 

[Cetmeman]

Thanks for all the help. Got a call the other day and looks like the place I ordered from gets their uppers from RRA directly and told me that my order would ship in 4-6 months. So i found a RRA LAR 9 from another dealer for a good price so I'm just going to get that instead. I was not getting the RRA lower because the CMMG was a bit cheaper and have just as many good things as the RRA.

 

[K-Romulus]

Thanks for all the help. Got a call the other day and looks like the place I ordered from gets their uppers from RRA directly and told me that my order would ship in 4-6 months. So i found a RRA LAR 9 from another dealer for a good price so I'm just going to get that instead. I was not getting the RRA lower because the CMMG was a bit cheaper and have just as many good things as the RRA.

ETA: Never mind, I misread your post (duh)

 

[ALBY]

my olympic 9mm AR runs on glock mags and that gun is awesome.

we have 5 guys with them at our club. they have been tested in our matches. they work and we all highly recommend them.