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Page AR-15 » Rimfire and Pistol Calibers
AR Sponsor: bravocompany
Posted: 4/25/2017 10:19:32 AM EDT
I'm looking to get into the 9mm ar pistol thing.  I was seeing some 9mm short barreled uppers in the EE that claim one can just slap them on a standard 5.56/.223 lower with no changes and they will work.  Is this true?
What makers of these complete uppers should I look for or avoid. All I've seen so far was RRA, Olympic, and PSA.

If I were to get one of there complete uppers on the EE to use on a standard pistol lower, what all would be needed?  Besides the mag block, would I need a different buffer/buffer spring.
I've read you need a different hammer but then I rear with these specific uppers, you don't need to do anything at all.

Here are examples I found on the EE: psa upper

olympic upper

could I buy either of these and just slap it on a pistol lower and be good to go?

Thanks
Link Posted: 4/25/2017 11:04:02 AM EDT
[#1]
As long as the bolt is ramped you are GTG with either setup.
Link Posted: 4/25/2017 11:20:18 AM EDT
[#2]
Quoted:
I'm looking to get into the 9mm ar pistol thing.  I was seeing some 9mm short barreled uppers in the EE that claim one can just slap them on a standard 5.56/.223 lower with no changes and they will work.  Is this true?
What makers of these complete uppers should I look for or avoid. All I've seen so far was RRA, Olympic, and PSA.

If I were to get one of there complete uppers on the EE to use on a standard pistol lower, what all would be needed?  Besides the mag block, would I need a different buffer/buffer spring.
I've read you need a different hammer but then I rear with these specific uppers, you don't need to do anything at all.

Here are examples I found on the EE: psa upper

olympic upper

could I buy either of these and just slap it on a pistol lower and be good to go?

Thanks
View Quote
You'll need a magazine block of some sort to use regular 9mm magazines (included with the PSA you referenced), or with the Olympic upper, you could use the Olympic magazines which do not require a magazine block. Other than that, most 9mm uppers should drop on.

Some of the uppers meant for use with glock mag lowers may not be compatible, or necessarily fully functional with a non-glock magazine lower.
Link Posted: 4/25/2017 11:45:08 AM EDT
[#3]
I run my AR9 on a regular lower.  Compared to a 5.56 rifle, differences are:

-Barrel
-Bolt
-Buffer
-Magazine
-Mag block
-Muzzle device

My lower uses a DPMS-style hammer.  Some hammers and some bolts are not compatible with each other.  

I can convert the lower back to 5.56 configuration, but it would require tools.  It's not a quick or "drop in" process.  My lower is equipped to use Colt mags with a Hahn block.  I'm happy with it.
Link Posted: 4/25/2017 2:08:55 PM EDT
[#4]
on PSA's site, they say their 9mm uppers are designed to be used on their 9mm lowers. Does that mean they won't work on the regular 5.56 lower or is that just PSA's way of not guarantying anything?

I just want a 9mm upper I can drop on a 5.56 pistol lower, throw in a mag block and go.  No hammer changing, no buffer changes.  So most 9mm complete uppers will do this?
Link Posted: 4/25/2017 2:41:36 PM EDT
[#5]
Discussion ForumsJump to Quoted PostQuote History
Quoted:
on PSA's site, they say their 9mm uppers are designed to be used on their 9mm lowers. Does that mean they won't work on the regular 5.56 lower or is that just PSA's way of not guarantying anything?

I just want a 9mm upper I can drop on a 5.56 pistol lower, throw in a mag block and go.  No hammer changing, no buffer changes.  So most 9mm complete uppers will do this?
View Quote
PSA and some other companies have uppers that are specifically made to be used with their dedicated Glock magazine lower receivers. The lower is modified, and the upper has modifications and extra parts to activate the bolt hold-open using the follower of the glock magazine. These will not activate the bolt hold-open if used on a regular lower, and may require fitting to work with a regular lower and magazine block common to the other "Colt pattern" 9mm uppers.

The majority of uppers out there are for the Colt pattern 9mm, which work using a regular lower, and a magzine block for dedicated Colt or modified Uzi magazines, and some other variations. They will drop on to any standard lower.

The Olympic pattern 9mm uses a different mag block, or special magazines, which are different from and not compatible with the Colt pattern magblock. The Olympic 9mm uppers will all drop on to a standard lower.

If your current hammer is notched, you will need to switch that to a non-notched hammer, which will also work for 5.56.

Depending on your current buffer and spring setup, you may need to change buffer weights to get something that will run properly with both the 9mm upper and your 5.56 upper(s) - that's going to be a trial and error thing based on the types of ammo you shoot in 9mm and in 5.56, both.
Link Posted: 4/25/2017 3:26:48 PM EDT
[#6]
Discussion ForumsJump to Quoted PostQuote History
Quoted:
PSA and some other companies have uppers that are specifically made to be used with their dedicated Glock magazine lower receivers. The lower is modified, and the upper has modifications and extra parts to activate the bolt hold-open using the follower of the glock magazine. These will not activate the bolt hold-open if used on a regular lower, and may require fitting to work with a regular lower and magazine block common to the other "Colt pattern" 9mm uppers.

The majority of uppers out there are for the Colt pattern 9mm, which work using a regular lower, and a magzine block for dedicated Colt or modified Uzi magazines, and some other variations. They will drop on to any standard lower.

The Olympic pattern 9mm uses a different mag block, or special magazines, which are different from and not compatible with the Colt pattern magblock. The Olympic 9mm uppers will all drop on to a standard lower.

If your current hammer is notched, you will need to switch that to a non-notched hammer, which will also work for 5.56.

Depending on your current buffer and spring setup, you may need to change buffer weights to get something that will run properly with both the 9mm upper and your 5.56 upper(s) - that's going to be a trial and error thing based on the types of ammo you shoot in 9mm and in 5.56, both.
View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Quoted:
Quoted:
on PSA's site, they say their 9mm uppers are designed to be used on their 9mm lowers. Does that mean they won't work on the regular 5.56 lower or is that just PSA's way of not guarantying anything?

I just want a 9mm upper I can drop on a 5.56 pistol lower, throw in a mag block and go.  No hammer changing, no buffer changes.  So most 9mm complete uppers will do this?
PSA and some other companies have uppers that are specifically made to be used with their dedicated Glock magazine lower receivers. The lower is modified, and the upper has modifications and extra parts to activate the bolt hold-open using the follower of the glock magazine. These will not activate the bolt hold-open if used on a regular lower, and may require fitting to work with a regular lower and magazine block common to the other "Colt pattern" 9mm uppers.

The majority of uppers out there are for the Colt pattern 9mm, which work using a regular lower, and a magzine block for dedicated Colt or modified Uzi magazines, and some other variations. They will drop on to any standard lower.

The Olympic pattern 9mm uses a different mag block, or special magazines, which are different from and not compatible with the Colt pattern magblock. The Olympic 9mm uppers will all drop on to a standard lower.

If your current hammer is notched, you will need to switch that to a non-notched hammer, which will also work for 5.56.

Depending on your current buffer and spring setup, you may need to change buffer weights to get something that will run properly with both the 9mm upper and your 5.56 upper(s) - that's going to be a trial and error thing based on the types of ammo you shoot in 9mm and in 5.56, both.
Circuits is absolutely right.  9mm buffers exist for a reason and I wouldn't trust a typical 5.56 buffer to work not just because of weight, but also because of length.

Stripped lowers are cheap.  Buy one and dedicate it to your 9mm build.
Link Posted: 4/25/2017 3:30:30 PM EDT
[#7]
good solid replies. Thanks everyone!
Link Posted: 4/30/2017 9:43:10 AM EDT
[#8]
I was new to the 9MM game and bought from Daytona Tactical their 16" 9MM COMPLETE RIFLE KIT STAINLESS STEEL BARREL WITH NO LOWER.  I needed another lower parts kit.  I put this on my Colt SP1 lower and it shoots great.  I have about 150 rounds down range American Eagle FMJ and some Federal HST 147 grain.  For the $460.00 dollars I could not go wrong.

Tony P.
Page AR-15 » Rimfire and Pistol Calibers
AR Sponsor: bravocompany
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