Looking for some wisdom setting up / building a 9mm AR

[dcmdon]

Hi all,

I want a 9mm AR. I should just go buy one from RRA with the dedicated lower thats machined for an UZI mag, but I have a "want".

I live in CT and would like to use a pre-ban lower that I have. Which means installing a mag block. I've heard these can be troublesome. I've also seen it at my local
club where we do a thursday night shoot. It seems that the converted lowers are less reliable than the dedicated ones.

I'm interested in any wisdom any of you may want to add to this discussion as well as any recommended people to do business with.

Don

 

[atilla]

i actually spoke to john at remsport about converting my olympic 9mm to take uzi mags instead--basically you'll want the hahn precision mag block. i have a different hahn block (the olympic uses sten mags) and it works like a champ so i'd be willing to be their uzi block is of the same quality.

i would not be too concerned about reliability, i rarely have issues with my olympic and: 1. it's an olympic, and 2. it's using WWII-era sten mags. if i can make that work a rifle using uzi mags would be a walk in the park.

i say go for it, it will be a fun rifle. i would have gone ahead with the conversion to uzi mags but the rifle already works fine and flintoid poisoned my mind with thoughts of drunkenly building an AK so i just blew all the money i was going to invest in the AR on AK stuff.

alternatively if you buy MY 9mm AR i'll clean it up nice and purdy for you.

...i need money.

 

[dcmdon]

atilla,

I've been told that there are 2 basic 9mm systems.

Olympic
everyone else

I've also learned that despite the fact that its made by Oly, its probably functionally superior. The only downside to the oly system is you are married to their mags, which are expensive.

So I'm not sure your Oly is reliable. Its an entirely different animal than most other 9mm conversions. If I've got my info right.

But you say yours uses sten mags huh? hmm.
Don

 

[jrbtzx12r]

I went with the Colt based system. Uzi mags are fairly easy to find and modify plus they're around $10ea. If you feel like paying the price for Colt mags they'll work without modification. Go with the Spike's magwell block. You can adjust the ejector and I have to say it looks identical to the Hahn, but a lot cheaper.

If you go with a CMMG upper pre-built you won't need the 9mm hammer so it's easy to convert back to a 5.56 lower if needed. Whichever upper you go with make sure it has the ramped BCG so you can avoid the 9mm hammer.

 

[dcmdon]

Thanks for all the good info.

Re CMMG vs RRA for the upper. I like the idea of using a stock lower as far as LPK parts. I'd guess the RRA is more accurate, just because thats what RRA does well. But this gun will be for pistol caliber carbine fun matches, nothing serious. Max distance will be 25 yards.

The Hahn block is $140 from brownells with my dealer account. Spikes is $150. So the price is close enough to not matter.

Which one is BETTER. The spikes seems to have a lot of adjustment built into it. Which could be a double edged sword.

Can anyone speak from experience re the difference between a hahns and a spikes.

Thanks again for all your help guys.

Don

 

[jrbtzx12r]

Something else to think about. CMMG uses W.A.S.P. (AKA melonite) on their barrels. So they're a bit more protected from the elements. I have two RRA AR's in 5.56 and they are nice, but the CMMG 9mm LE upper is very impressive compared to them and I haven't had a single problem with the upper. I feel the coating is worth going with them.

 

[andyc4728]

I'm not an expert on 9mm ARs by any means, but I have a rock river 9mm AR and have been very happy with it. It's a good shooter and quite reliable.

 

[dcmdon]

Andy,
did you buy an entire gun or just an upper and a mag well?

jrbtzx - Yes melonite is great stuff. I wonder if the inside of the bore is melonited. Its that tough. Realistically for me, the better protection isn't relevant. The gun will be a pure toy, used for pistol caliber carbine matches. One thing that IS relevant to me re teh CMMG is the fact that you don't need a special hammer.

I only wish CMMG would offer a configuration I liked. I really have no interest in any gun with a barrel with grenade launcher cuts.

 

[andyc4728]

I got the complete rifle from them. It's a pretty simple setup, A2 stock, A2 carry detachable handle and mid length front site. Pinned break right from RRA.

It's a fantastic plinking gun and is VERY quiet with 147 gr 9mm loads.

 

[jrbtzx12r]

Andy,
did you buy an entire gun or just an upper and a mag well?

jrbtzx - Yes melonite is great stuff. I wonder if the inside of the bore is melonited. Its that tough. Realistically for me, the better protection isn't relevant. The gun will be a pure toy, used for pistol caliber carbine matches. One thing that IS relevant to me re teh CMMG is the fact that you don't need a special hammer.

I only wish CMMG would offer a configuration I liked. I really have no interest in any gun with a barrel with grenade launcher cuts.

W.A.S.P. is actually applied to the inside of the barrel. Check it out.