9mm?

[Optimus Prime]

I've got a couple neked lowers hanging around here and I've been kicking the idea of a 9mm AR around. What kind of advice do you guys have in regards to this?

With the little bit of stuff I've dug up on various manufacturers' sites, I'm leaning towards starting off with a RRA midlength upper (I'm lazy so I don't feel like jumping through NFA hoops, so I want to stick with a 16" barrel, and those look plain stupid with a carbine length "system" (handguards in this case) plus more sight radius is always a plus.)
I also want to just stick with a Magpul MOE handguard (already have a super stubby VFG for it, and the only other thing I would hang off the thing is a light, so why bother with a 10lb rail farm?)

I guess my questions are simply who, if anybody, has 16" middy-type 9mm set ups (I'm not opposed to building up the top either, so it does not need to be a complete upper,) who should I avoid, and what mag block set ups are the good ones?

[Quentin]

I guess my question is what is the purpose of this AR and does 9mm make that much sense in the first place, or any pistol cartridge (for your purpose). No doubt it would be fairly cheap to shoot and ammo is everywhere but ballistically what does it give you in a rifle, certainly not much after 100 yards. Not trying to change your mind it could be interesting but I wonder if a rifle chambering might be more useful. To me, a .22LR upper would be much more useful.

[Optimus Prime]

Mainly, it's cheap (my shooting buddy's already set up for reloading cast 9mm,) and I've already got 5.56 ARs and an M&P15-22, so changing things up could be fun. I'm sure it would be more than enough for home defense as well. It's 75% S&G, and 25% CCW you could say. More importantly, the "why" isn't that important

[Emilio84]

I am running the spikes upper.. I contemplated getting the Rock River Arms upper but the billet upper, ramped bolt, and my friend's dealer discount swayed me. AIM surplus has the spikes 9mm uppers for a good price at the moment.. and no 3 week wait like I had. I am using a slash heavy 9mm buffer and a wolf XP carbine spring along with an SSA trigger and VM HYtech mag block to round it out.

I absolutely LOVE my 9mm ar. It may not be the most practical rifle but it is just so much fun to shoot and with the VM block i can buy cheap PREBAN (important for us NY'ers) 32rd magazines for about $8 a pop.

Some things I would suggest no matter what you go with.

1. Buy a quality block and magazines. These are what cause 99.99 percent of the issues. If you go colt patten stick with a hahn block and metalform magazines.

2. Get a ramped bolt or have yours ramped. Cheap insurance

3. Get upgraded trigger/hammer pins (blockback is tough on the pins) I went with KNS anti rotation pins but you can just get some stainless pins and be good to go.

4. If you don't get a ramped bolt be sure to get a proper 9mm (rounded) hammer from RRA

Let us know what you decide!

[Optimus Prime]

I've been using KNS pins in my 5.56 carbine since I built it, and I was fully intending to drop them in this one too, if only because I like how they look.

I can't seem to find the ones at Aim though, do you have a link?

[Emilio84]

Hmm looks like they are out. Sorry for the bad info. I run KNS pins in all my AR's as well.. for the same reason.

[Optimus Prime]

Anybody have any experience with Spike's mag block? I like last round hold open...

[hikeeba]

Howdy. My 9mm AR was my first AR. I decided to start with 9mm AR because at the time I was visiting an indoor range quite frequently, and they do not allow rifle calibers there. I figured since I was mostly shooting a 9mm handgun, a 9mm AR would be a good way to go. I rented the range's 9mm AR, A basic Olympic Arms 16", and liked it. Afterwards, I talked to a couple of the employees about the OA 9mm, and they had nothing but good things to say about it. They said it was a real workhorse, and that it was rented often, didn't get near the amount of cleaning that it should, but it just kept right on running. So, I figured I go down that road. And (knock on wood), I have zero problems, and have been very pleased with the upper. I've always cycled cheaper new-manufactured (WWB, Rem UMC) through the upper, and it has never had a hiccup. It runs like a top.

I run straight Sten magazines with flattened ears with a Hahn drop-in block. I like the fact that I can drop the Hahn block into any of my lowers and run the upper. When I originally put the firearm together, the Sten magazines were cheap and plentiful, but now, not so much. I see that Oly has developed new magazine for their 9mm AR - $45 a pop - ouch. And I'm guessing it is a proprietary design to go with a new feedramp setup - double ouch.

I really like my Oly setup because it is simple, and it works well. But in light of the changes Oly has made to their 9mm AR platform, I have no idea as to the reliability/durability of the new stuff, so I can't give it a thumbs up or down.