Tell me about 9mm AR's.

greenlion said:

Someone explain why you would want a 9mm AR in the first place. If you are shooting it outside, the 223 has more range and power. If you're shooting it for defense inside, a pistol is more maneuverable, plus distances are short so there is no need for longer barrel.

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I use mine as a "training tool". I set it up to replicate my HD carbine in 5.56 to include furniture and optic. I've also got a dedicated AR in .22LR and a conversion unit, but because it recoils the 9mm more than a .22LR it's more a realistic trainer. My wife and son (12yrs old) also shoot it regularly and don't realise they're training for the "real thing".

The use of 9mm allows me to shoot my AR500 tgts at CQB distances whereas .223/5.56 would tear the chit out of them. Also 9mm carbines are allowed at most indoor ranges where 5.56/.223 is not. We have a local trainer that often puts on HD classes that allow PCCs or shotguns, but not HP carbine unless you're using frangible ammo ($$$). Also, although I reload both 5.56/.223 and 9mm (and 30+ other calibers) I find 9mm easier/faster. No trimming, no case lube etc. just warm up the Dillon and say hello to 400+ rds an hr.

From yesterday doing VTAC 9 hole drills at 35 yards on my steel plates:



So basically for me, it allows me to get in some training in that I can't do regularly and at a reduced cost. Should the Zombie Apocalypse happen, it's a viable defensive tool, but that's not my primary use.

IF you're not into training etc. they're also a blast to plink with.....

Chuck

Reloading 9mm is easier than reloading 5.56. I keep identically setup 9mm and 5.56 ARs. Can be shot at many indoor ranges where 5.56 is prohibited. Not so hard on steel targets. My 9mm AR is my favorite rifle, but my 5.56 AR is my rifle for serious occasions.

I suppose that makes sense.

Someone explain why you would want a 9mm AR in the first place. If you are shooting it outside, the 223 has more range and power.

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Costs less to buy or reload ammunition, makes less noise, runs perfect with subsonic ammunition and you can't have one of everything without one.

greenlion said:

Someone explain why you would want a 9mm AR in the first place. If you are shooting it outside, the 223 has more range and power. If you're shooting it for defense inside, a pistol is more maneuverable, plus distances are short so there is no need for longer barrel.

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I haven't built one yet but I intend to some day. As some have mentioned it's great for cheap training. I cast my own 9mm bullets, which makes 9mm cheaper than .22 LR for me.

I'm working on a home fabricated 9mm AR using unmodified Uzi mags. I still may get a drop in mag block for Colt/ modified Uzi mags because I plan to Form 1 an SRB receiver in 2016, so I could have a 9mm and a 5.56 upper on the same SBR.

I'm building the dedicated 9mm lower as a pistol anyway.

jmorris said:

Costs less to buy or reload ammunition, makes less noise, runs perfect with subsonic ammunition and you can't have one of everything without one.

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This^^^^, AND in addition to what all the other folks have said, running a 9mm suppressed is much quieter than a suppressed 223.

And they are just stinking fun to shoot!

Or the Beretta CX4 with some trigger upgrades and better sights.

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With the higher capacity mags the Beretta is not a terrible option. Nice and handy. But the trigger is the worst ever. I did not know that trigger upgrades are available, that would make a big difference.

However, if you run a standard AR, an AR-9 is still a better choice because there is a zero transition (ergonomically) from one to the other. More time on the AR-9 makes me better with the AR-15. Just a consideration.

I agree with a lot of what others have said, primarily that 9mm is so easy and cheap to load that is now my primary rifle except for precision.

It took 22 posts for someone to question the utility of a 9mm AR. It usually happens within the first 10 posts on these pistol-caliber carbine threads.

BTW, I have a CMMG 9mm AR. It is super-accurate, but I've had a few issues with reliability. I bought a couple Metalform mags that were not 100%, but I just returned them. I also had a couple malfunctions that, in my opinion, were essentially related to quality control. My buffer tube wasn't screwed in far enough to fully engage the buffer retainer pin, which eventually produced a nasty malfunction. Later, my bolt catch spring failed for no apparent reason. Both issues were easily fixed, but it irked me to encounter such failures out of the box on a fairly expensive gun.

Looking to build a 9mm AR. So far I've done some research and if you've built one tell me what you liked or what you would do differently and why...

Colt/Uzi stick mags or Glock mags?
Colt Mags...Brownells makes excellent quality ones and you can get an X Products drum mag plus no chance of putting wrong caliber mag in the gun

Hahn magwell block or dedicated lower?
dedicated lower...CMMG MK9 is good price and why have extra parts when its not necessary

Ramped 9mm bolt?
Depends on trigger

How to reduce wear or wallowing of the hammer pin holes.
haven't experienced this problem yet

What buffer and bolt weight do you run, and have you tried an AR10 buffer spring? Blitzkrieg Components Hydraulic Buffer...i forget what spring they recommend with it (possibly barrel length dependent)

Anything else you can tell me?
They are so much damn fun. Haven't had anyone try it who wasn't addicted. We spend an hour or 2 ringing steel everytime i take it out.

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Very fun stuff. I went with an X products SCU (the pistol length Outlaw upper) and I really really really like the Side Charging Handle on it....

Definitely get the Brownells magazines if you go Colt SMG

-Matt S.

Who makes the Brownells magazines? I've had great luck with the Metalforms in my Colt.

If you like the Metalforms, PSA is rebranding them for a lower price. Same magazine, just has crossed cannons on the floorplate.

http://palmettostatearmory.com/psa-9mm-smg-magazine.html

My next project is a QC10 based build, either a Carbine or a SBR/PDW. Makes perfect sense to me as my EDC is a G19 and the QC10 will run any double stack Glock mag on the market from the 10-rd G26 to the 33rd G18 extended.

If your not stuck on the AR pattern, you might consider the CZ EVO3 ... technically it's a pistol but if you can SBR in your state, it's THE stuff and even if you can't do the SBR there is an arm brace adapter ... I filed my form 1 the day I picked up mine and got the adapter to use until CZ has the 922r kit available and my form 1 comes back ...



You can pick up the gun for under $800 and 30 round mags for $20each ... I've been happier with this purchase than any gun I've bought in the last several years! I've got about 600 rounds through it, of everything from Walmart cheapo WWB, Remington JHP golden sabers to 147 subsonics and ZERO malfunctions.

1) Colt Magazines. Brownells makes copies, they appear to be identical to the Colt's (Metalforms) of the past, with a better finish and a lower price.

2) No dedicated lowers when I built mine, today I would probably use one.

3) I've been meaning to ramp my bolt for years...

4) Ramping the bolt helps, I use KNS(?) pins.

5) 9mm buffer, standard CAR spring for an M4 stock.

I had issues with bolt catches breaking on an empty mag, I shortened the cycle by dropping quarters in the receiver extension. No problems since. Over 15k rounds fired.

It seems like I had another issue, but cant remember what.

Edit: The roll pin holding the extractor worked its way out of position, took a while to figure it out. I simply replaced it with a longer one.

I've seen PSA and Brownells are offering Metalform or Metalform-like mags at better prices, but I wish they would offer the 20rd mags too. I really like the 20s.

Speaking of magazines, here are some photos of a 71 round Suomi drum I modified to work in my 9mm AR.