OK, Thinking about getting a 9mm AR. Considering a Colt but would like you alls advice on brands?
Just waning to be in the know before I buy. Have 5.56 guns so the  familiar with the AR platform.
Thanks

I have had good luck with my RRA 9, but I really think I should have gone SBR or pistol/sig brace.

The 16" gun shoots well, my feeling is that a 7-8" bbl would be better suited to the caliber.
Gotta say it is a lot of fun.  Low recoil and muzzle blast are great for getting first time shooters used to the platform.

If you get one, get a lula mag loader.  They are a pain to load by hand.

Get Spartan Glock mag lower and build from there.

Colt 6951, then SBR it

If you do get a Colt 6951 be sure to tighten down the barrel to the correct torque before firing; several of them have come loose.  The 6951 is made periodically, not year round, so availability varies.  It works fine as is; if you start messing around with it then you can get lost in the weeds real fast.  We in the forum can help you set it up right.

Mags from Colt, Brownells, and Metalfrom are all the same and all work just fine.  The Brownells no-questions money-back guarantee is excellent (and applies to everything they sell).  ASC magazines work just fine in the Colt 6951; people seem to have trouble with them in other makes.

I have a like new in box Colt I may sell.  I will put it in EE.

I've built 2 with Glock mag lowers, DDLEs (now QC10) & Spartan. The Spartan is a great buy. Magazine choice usually depends on what type mags you have on hand. If you plan to use a suppressor on it get a 5 to 5.5 in barrel to keep the ammo subsonic, pus it helps get down the OAL when you put the suppressor on. They are lots of fun to shoot.

do it..


PSA 16" 9mm upper
PSA 9mm build kit
kits combined are $510 plus shipping..

less than $580 with your AR lower (or 80%)

I did my SBR from a RRA 9mm carbine. I bought and shot it with the 16" barrel while the paperwork was being done. After it was completed, I replaced the barrel with a RRA 10.5" one and added a Midwest Industries handguard. I sold the 16 " barrel to offset the cost and never looked back. I waited for RRA to release their 9mm only lower so I could not have to mess with magwell adaptors and blocks, that system is an antique nowadays. The newer lowers that are sized to fit the Glock and Colt pattern magazines look really nice. Lots of good choices for some really great guns, too bad I'm not looking  to do another one.

Only have one at the moment built on a QC10 Glock lower and 5.5" barrel.  Shoots 100% for me using my ammo, mostly 124gr RN but it also eats JHP without a problem after switching to the QC10 barrel.

Stupid fun gun to shoot with same manual of arms as a AR (obviuosly) and about the same felt recoil in my particular build as a 556 so cheap way to shoot without getting confused on controls.   I paired it with a titanium F1 can, had an Octane on it prior but it deserved its own dedicated can.

The only downside is the bolt fails to lock back on the last round probably the majority of the time.   I'm looking at the new upper coming to market that purports to solve that for glock based builds and if that works then I'll swap the upper out and have the best of both worlds.  

I'll probably also pick up an 80% lower from the same company to mill out another build, they're really that much fun to shoot.

Possibly the best use for a glock mag is a lower built for one.  The 2 position feed colt/uzi mags work, mostly.
They do have their flaws.

tomcat, did you ever pull the trigger? (pun intended)

I'm thinking CMMG lower and build the way I want.

I bought a colt 6951 and it has been flawless...I see a lot of people having to tinker with their shit...I don't it just works...

?
most of the time you buy an off she shelf rifle, you dont have to tinker with it to get it to work.
but it also isn't usually set up EXACTLY like you want (correct barrel, handguard, stock, etc.)

and, generally, it cost more.


even the 6951 takes a magwell insert, so it's not like you're really any different off than that PSA combo that I linked above.  (but I dont think the colt uses a ramped bolt, does it?)

Read as much as you can and build your own. I was sold on my old school 16" CMMG and never had a problem but it's one of the guns in the safe that didn't get much use. I really like the reviews the QC10 lowers are getting and it's that time of year that I gravitate to the indoor ranges, thus starts the money pit (SBR, QC10 lower, and suppress).
So, I start to tear this thing down and find it has a un ramped RRA bolt and matching FCG (not the end of the world but I want to change to a short throw/reset FCG so time to ramp the bolt and I was fairly certain they told me it came with a ramped bolt when I purchased it). We're going back 6+ years but this was a dedicated CMMG 9mm receiver with a bottom loading Hahn's block design and they were local and I had a lot of access to their guns at local shows and staff was great so this is what shocked me. I go to remove the handguard and the allen screws are saturated with red lock tight and "none" except for the two large ones came loose (stripped the allen heads and I've been a car tech for 30 years using heat, lube, and Snap On allen wrenches-I can't believe their shop assembled it like this). So off to the mill I go and machine the heads off so I can remove the handguard. Now for the real shock, thank god the red loctite had the handguard secured, because once it was off I simply unscrewed the barrel nut by hand. When I originally bought the gun, the rail on the receiver and handguard were off to the point that the optic wouldn't mount, John had me send them the upper and they fixed the issue and sent it right back (high marks for politeness of their staff and customer service, but looking back on things I'm betting they couldn't get the damn screws loose so the turned the handguard while still secured to the barrel nut and loosened it.
Over the years I've learned to build a lot of what I shoot. Up until last week I would have given them a 10+. It may have just been a fluke but I really did expect better like we do with a lot of the big names. I was thinking about buying a CMMG ramped bolt, but now I might just have the RRA ramped and be done with it. If you build it yourself, you know exactly how it was assembled and you get the exact parts you want. Lots of 9mm stuff available today, not like years ago, so read up-choose wisely-double check everything, even if you didn't build it.

Edit: disregard...

I better stop before I start.  When I see the word PSA...

Well, PSA screwed me on two purchases early on.  I think PSA is trash.  Nuff said.

Just traded foe a new Colt. Shoots perfect. Didn't know about the barrel might be loose. Have built 556 kits in the past. Need to know the torque specs. Thanks.

snug it up then give it a "little extra".
done..

I had to take one in to a gunsmith today for this exact issue.  He said that specs called for 30-60lbs but that Colt was torqueing them around 27-28lb hence why they come lose.  He tightened mine to 50lb.  Earl

27-28# ??
that's barely more than finger tight  (CRAZY) you have to almost try to torque it so low.


with the sales this week, I picked up my 9mm build kit pieces.. now, I'll be looking for a barrel/handguard/upper receiver!