Anyone built one? I'm picking up an NFA billet AR9 (glock) lower this weekend. Probably gonna pair it with their billet side charger upper. 8" barrel and a kak shockwave.

Any tricks or tips for a build? I'm told they are finicky, and hard to be reliable... but hey, I don't mind a challenge.

Thoughts?

Thanks!

I got a CMMG colt mag lower and built it up with a sig brace. I've tried a couple of different configurations on the upper but most of the shooting has been done with an NFA side charger(really like it) on a 5" 3 lug barrel.

I've monkeyed with the buffer setup quite a bit. Currently running a JP SCS(9mm version). They're nice but expensive. Prior to that I really liked the VLTOR A5, 6.8 oz buffer. I've tried various springs (CS, buffer length, carbine length etc).

Stuff I've heard(can't verify 100% as an actual issue besides internet comments) are issues with the bolt catch breaking. It's that reason I went with the A5 buffer. It's longer (the JP takes care of this also), which compensates for the shorter length of the case so the bolt doesn't have the "running room" to build up momentum that may damage the bolt catch.

With the glock mags that may not be an issue with the lack of BHO on some of the lowers. I know NFA has their bho upper but haven't handled one to know how solid that system is.

I had issues with cycling early on but at this point I'm chalking it up to weak reloads. A heavier buffer/spring combo will help tame recoil but could be an issue for weak ammo. It's also a lot of mass moving around so it won't be as smooth as an AR. It's not rough but it's harder to keep the sights steady.

It's fun when you get it dialed in and they can be really quiet with a can.

Thanks Nate, much appreciated sir!

In all honesty, I wanted to build a .308 AR10, but I'm tired of waiting for the receivers to come back in stock. Lol.

He New Frontier armory stuff is surprisingly affordable.

I LOVE mine. It's the softest, quietest gun I own, but it is picky. As far as buffer systems, look at JP, they've been doing it for a while and have a reputation for quality and reliability. I've seen their complete guns run flawlessly, when mine was choking on worn mags (although empty mags don't lock the bolt). Do keep tabs on your potential investment since a nice factory rifle can be had for about 17. Also, don't put too light of a trigger in it. Don't ask me how I know.
Good luck! Keep up posted.

Dan1612 said:

I LOVE mine. It's the softest, quietest gun I own, but it is picky. As far as buffer systems, look at JP, they've been doing it for a while and have a reputation for quality and reliability. I've seen their complete guns run flawlessly, when mine was choking on worn mags (although empty mags don't lock the bolt). Do keep tabs on your potential investment since a nice factory rifle can be had for about 17. Also, don't put too light of a trigger in it. Don't ask me how I know.
Good luck! Keep up posted.

Click to expand...

I should be in to this one for $750-900 depending on what handguard I go with... probably going to stay with a milspec trigger. I may put a geissele trigger in it at some point. We will see.

With the price of building a 9mm AR and the inherent pickiness or teething problems to get one to run right, why dont people buy guns designed around the cartridge? ie CZ Scorpion or Sig MPX or any of the other smg type variants.

I like the idea of having standardized controls but even that is not 100% with some of the 9mm ARs.

I considered building one before but ultimately picked up a Scorpion.

I don't like scorpion ergonomics or the cheap, plastic feel of the thing. MPX is a contender, and has great AR style ergonomics but my pistol version. felt a little snappier than I expected, and like the scorpion, it takes weird mags.
With fresh mags and quality ammo, mine runs great. I'll need to run a few more matches before final verdict though.



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John,

If you've got time this weekend, you can saying by and I can show what I've put together. I might try to get to the range Saturday.

Something to keep in mind with the job SCS if you'll need a bolt with a hollow center at the rear. Some of the newer "modular" bolts don't do that. There are several 9mm specific buffers out there too.