What do I need to use a 9mm upper on my SBR lower AR15?

September 08, 2017, 08:18 AM

barndg00

I'd like to get a 10" or so barrelled 9mm upper to use suppressed. I already have a SBR'd lower, in 5.56. I'd like to be able to go back and forth between 9mm and 5.56 (though I realize this will at minimum involve installing a magwell adapter in the lower). Please educate me on what I would need to accomplish this.
I'm guessing a bolt carrier that works with standard style AR hammer, a magwell adapter, and possibly a different buffer?

September 08, 2017, 08:25 AM

PGT

9mm buffer, spring, BCG, mag block and mags. KAK and QC10 are good resources for parts.

September 08, 2017, 10:14 AM

MG34_Dan

Just watch GB and get a cut up ex-PD Colt 9mm AR15 SBR/SMG parts kit. They do appear regularly and are reasonably priced.

September 08, 2017, 03:15 PM

billnchristy

Jse surplus has some complete uppers for 450 right now and come with the pro mag removable insert. They aren't the best but work with colt mags and I hear reliability isn't bad. I had one but never completed it.

Link
http://www.jsesurplus.com/CUST...9MM&utm_medium=email

September 08, 2017, 03:35 PM

RogueJSK

There are some 9mm mags out there that don't require a magblock. For example, Olympic Arms made 9mm mags that fit in a standard AR magwell.

They're expensive and overly chunky, but may be worth it so you don't have to keep installing/uninstalling the mag block (which typically requires removing the bolt catch each time).

The real downside is that you have to use an Olympic-style upper with integral ejector, so you can't use just any old 9mm upper.

September 08, 2017, 09:41 PM

Verne

Like a lot of people this year PSA's daily emails proved too tempting, especially their 9mm uppers. The one I purchased was listed for their Glock mag lowers. After some research, before I bought, I found out they should work on a milspec lower. So I gambled and won. I can confirm that their 9mm upper for the Glock mag lower will work on a standard lower.

This lead to me looking for a mag block which landed me at http://www.torkmag.com/g-block.html for a Glock mag magwell block.

My G-block was delivered Tuesday and was able to put 50 rounds through it Wednesday without a single issue.

I'm very happy with it and think it is a good option if you already have Glock mags (which I did not) and $75 to spare on one.

Another option for consideration.

September 08, 2017, 11:13 PM

JJexp

quote:
Originally posted by Verne:
Like a lot of people this year PSA's daily emails proved too tempting, especially their 9mm uppers. The one I purchased was listed for their Glock mag lowers. After some research, before I bought, I found out they should work on a milspec lower. So I gambled and won. I can confirm that their 9mm upper for the Glock mag lower will work on a standard lower.

This lead to me looking for a mag block which landed me at http://www.torkmag.com/g-block.html for a Glock mag magwell block.

My G-block was delivered Tuesday and was able to put 50 rounds through it Wednesday without a single issue.

I'm very happy with it and think it is a good option if you already have Glock mags (which I did not) and $75 to spare on one.

Another option for consideration.

Man I wish I had found that 2 days ago. I ended up tracking down a pro mag block and settling on that because affordable magwell adapters are becoming neigh on impossible to find.

September 10, 2017, 08:36 AM

kimberkid

quote:
Originally posted by MG34_Dan:
Just watch GB and get a cut up ex-PD Colt 9mm AR15 SBR/SMG parts kit. They do appear regularly and are reasonably priced.

That's what I did ... extremely happy with the outcome, plus mine came with a 3-round burst trigger that I'd been wanting for my M16(it didn't stay in there long but I wanted to try it) ... The mag-block is held in with the mag catch plus it has tension pins which can be tightened up with an Allen wrench; they slide out of the sides and lock the block into the magwell so drilling and pinning it into the magwell isn't necessary.
Anyway, all the parts are there except the receiver and you know everything works together ... It's a no guess work "build".