9mm AR15s...What is available?

[Sundance]

I have seen the Olympics and of course the Colts. I see that RRA advertises 9mm uppers also. What is the deal? What mags do the different ones take? Is it a temporary conversion that is easily switched back to .223? I saw that one maybe uses modified Uzi mags. Who modifies them? Are they reliable weapons or just toys for plinking? I know Olympic welds on a spacer to each mag (I don't like) and others use a drop in mag well converter (sounds better). Tell me all you know. I am dumb on this topic and would like to learn more. Thanks!

[Redlg155]

The Colt and Rock River are basically the same type, with the Rock River built on the Colt pattern. They both use a drop in mag well adapter. These are set in place by dropping into the magwell and turning an allen head screw that locks it into place. The advantages are that you use your standard magazine release. You can also use Colt magazines or modified UZI magazines in this style system. The Colt magazines will run you upwards of $100 each. The modified Uzi around $25-$35 each.

The Olympic uses special modified magazines as you had mentioned or you can get a SOCOM style block and use unmodified Sten magazines which are relatively inexpensive. The downfall is that with this system you use a "paddle" type of release instead of your normal magazine release. Also the 30 rd sten mags seem excessively long to me.

ASA also makes a 9mm model, which I don't particularily care for. Their uppers look like modified A2 uppers instead of a dedicated 9mm upper like the Colt and Rock River. They also make a mag block that drops in from the top instead of the traditional Colt type.

The conversion is temporary unless you buy a Colt that has a dedicated lower. With those the mag blocks are pinned in place.

All of my experience has been with the Rock River and Colt guns, so I can't tell you too much about the Oly system except that they are also blowback operated. The RR/Colt style has a bolt that is a bit different than the .223 bolt. No locking lugs. The bolt is held against the chamber with just recoil spring pressure.

If you want to go the RR way you would need the following.
1. 9mm Upper reciever complete w/bolt. $365.00 from Sable Co. (http://www.sableco.net/)
2. Mag Block $120-$125 average
3. 9mm Hammer $15
4. 9mm Buffer in a carbine type stock $22. Some folks like to use the standard buffer in a full length A1 or A2 stock. If you use a 9mm buffer in a A1 or A2 stock you will need a spacer. Rock River makes one out of polymer.

Also, check over at AR15.com in the pistol calibers section. They have a "sticky" posted over there that will answer all of your questions in more detail than I have provided.

The bottom one is my RR/Bushy 9mm AR. Chopped the removable carry handle so I can mount an Aimpoint Comp M w/ ARMS #22M68. Also RR Shorty stock w1" DPMS stock extender. http://www.imagestation.com/picture/sraid37/p0327968fbf2b22a72e558ee3fe00602a/fd1b3bbc.jpg

Either way they are a lot of fun. I'm on my second RR 9mm and plan on building a couple more.

Good Shooting
RED

[Sundance]

Thanks for all the great info!

Question...I have found a few sources for Uzi mags...where would I get them modified and how much per mag to modify or can you buy them already modified from somewhere?

Also, does anybody make a muzzle brake for a postban 9mm AR that looks like a real preban flash hider (like the wilson combat and the cav arms ones)?

Thanks!

[jason10mm]

I think the Oly one is the only one that uses a stock lower. With the RRA and the Colt you should change out the hammer, though I think they will sorta work with a 223 hammer. LAter.

[jb26]

I was under the impression that the OLY uses the standard mag release and the Colt/RRA uses the release that is part of the insert.

Also, the mods to the lower are temporary, but obviously the upper must be dedicated to the caliber because of the chamber and barrel dimensions.

[Molly]

I bought the Oly 9mm upper and attached it to a standard Bushmaster XM lower. It worked perfectly and I didn't do a single thing but put it on and push in the pins.

That was a great gun - super accurate, no recoil, fast and not too noisy. If you've ever shot a high-end paintball gun super-fast, thats what it felt like. I can't think of a better plinking gun. I used a mag well block that slid up into the magazine well from the bottom and clipped in. On the front of it, it had its own mag release which allowed Sten mags to click right in. I never removed it, and it worked perfectly. See photo. I can't say that all of the Sten mags were so great, but for the most part it was awesome. Some of the Sten mags were just really hard to load and seat the top round into properly.

I would have kept it but I someone offered me a new HK I had been wanting so I traded. The AR15 9mm is one gun I will definately buy again.

I took this picture before I sold it.