9MM AR

[STS556]

I am really looking into building a 9mm AR but I don't know too much about pistol caliber rifles as I don't have a pistol permit. I can't seem to find the answers I need so I am looking for some advice as far as legality and parts from anyone who has a 9mm AR.

1) I would build it with a 16" crowned barrel. I don't think I do but do I need a pistol permit for a barrel 16" or longer? The answer to this question will make or break the build.

2) I would be using a dedicated 9mm lower. Are any parts interchangeable between 5.56 and 9mm?

3) I would want a detachable mag so it has to be compliant. Would any of the compliant stocks like the Thordsen fit the 9mm lower?

4) It seems like the only way to go is a blowback BCG. Is this correct?

Thanks in advance for answering these noob questions.

 

[Robin]

Home - Just Right Carbines
These are probably cheaper than you could build one and they're made in Canandaigua NY
Robin

 

[ArmedCorgi]

I am really looking into building a 9mm AR but I don't know too much about pistol caliber rifles as I don't have a pistol permit. I can't seem to find the answers I need so I am looking for some advice as far as legality and parts from anyone who has a 9mm AR.

1) I would build it with a 16" crowned barrel. I don't think I do but do I need a pistol permit for a barrel 16" or longer? The answer to this question will make or break the build.

2) I would be using a dedicated 9mm lower. Are any parts interchangeable between 5.56 and 9mm?

3) I would want a detachable mag so it has to be compliant. Would any of the compliant stocks like the Thordsen fit the 9mm lower?

4) It seems like the only way to go is a blowback BCG. Is this correct?

Thanks in advance for answering these noob questions.

1. No. If you are building a rifle the shortest barrel you can have is 16". So as long as the barrel is 16" you are fine. No pistol permit needed, unless you are building a pistol.

2. Yes. Most AR15 lower parts will work fine. The exception for me on my build is that the BCG I bought, doesn't clear the last round bolt hold open that is designed into the lower I bought. So do your research when it comes to that so you don't go through the same frustration I am currently going through.

3. Yes they will fit.

4. Yes, with exception to CMMG's special upper. The name escapes me at the moment. They have an upper with a bolt system that locks like an AR's but its mad expensive right now.

@Bullet Guy

 

[Celt]

I like anstadtarms.com. dedicated upper/lower with glock mags.

 

[togmaster]

PM me and I can show you the one I built. Easy as pie.

 

[timboy]

Just a heads up,allot of chain stores won't sell you pistol ammo without presenting a pistol permit,real gun stores should not be a problem however.

 

[STS556]

Thanks for all the reply's everyone. You answered my questions.

I am not opposed to buying a complete one. I just enjoy building things.

I have heard about some stores not selling pistol ammo without showing a pistol permit. I just have to find which stores will sell.

And togmaster, I am close by so I will take you up on that offer. I'll PM you to set up a time and place.

 

[Marine Cpl]

Thanks for all the reply's everyone. You answered my questions.

I am not opposed to buying a complete one. I just enjoy building things.

I have heard about some stores not selling pistol ammo without showing a pistol permit. I just have to find which stores will sell.

And togmaster, I am close by so I will take you up on that offer. I'll PM you to set up a time and place.

And worse comes to worse, you could always drive to Pa and get bricks of 9mm.

 

[ArmedCorgi]

Thanks for all the reply's everyone. You answered my questions.

I am not opposed to buying a complete one. I just enjoy building things.

I have heard about some stores not selling pistol ammo without showing a pistol permit. I just have to find which stores will sell.

And togmaster, I am close by so I will take you up on that offer. I'll PM you to set up a time and place.

Keep us updated with your progress!

 

[Target]

The same rules apply to a PCC ( pistol caliber carbine) AR9 as to rifle caliber in regards to Safe Act.

A pinned mag AR9 sucks to reload.
Many parts are interchangeable like LPK , stocks, grips ,trigger groups, fore ends. Some brands more than others.
Buffers and springs are PCC specific.
Some manufacturers offer Last Round Bolt Hold Open, most do not.
Blow back is the only option.
You can get Glock or Colt magazine lowers for AR9s ( can't think of any others off the top of my head).

 

[Calculon]

I built one and documented it here:
My AR9 build finished!

It ended up being much more expensive than I thought it would be, but I enjoy building stuff too. You can definitely buy a complete AR9 cheaper than building it yourself. I really like the extended enhanced trigger guard from @Bullet Guy . Allows you to use a standard style stock vs Thorsden.

 

[STS556]

The same rules apply to a PCC ( pistol caliber carbine) AR9 as to rifle caliber in regards to Safe Act.

A pinned mag AR9 sucks to reload.
Many parts are interchangeable like LPK , stocks, grips ,trigger groups, fore ends. Some brands more than others.
Buffers and springs are PCC specific.
Some manufacturers offer Last Round Bolt Hold Open, most do not.
Blow back is the only option.
You can get Glock or Colt magazine lowers for AR9s ( can't think of any others off the top of my head).

Thanks. The rail was my next question. Do I have to choose a lower based on weather I am using Glock or Colt magazines?

 

[STS556]

Keep us updated with your progress!

I will. I contacted BulletGuy about the parts and he can get whatever I need.

 

[STS556]

I built one and documented it here:
My AR9 build finished!

It ended up being much more expensive than I thought it would be, but I enjoy building stuff too. You can definitely buy a complete AR9 cheaper than building it yourself. I really like the extended enhanced trigger guard from @Bullet Guy . Allows you to use a standard style stock vs Thorsden.

I will look through your build thread for inspiration.

 

[STS556]

And worse comes to worse, you could always drive to Pa and get bricks of 9mm.

Hell yeah!!!! Route 940 Gun Shop in the Poconos, no questions asked.

 

[Eddie Gunks]

Do I have to choose a lower based on weather I am using Glock or Colt magazines?

Yes

 

[STS556]

Yes

OK. It seems like the Glock lower is more common.

 

[Eddie Gunks]

OK. It seems like the Glock lower is more common.

Common does not matter.

If you have glock pistols, maybe glock is the way to go.

I run glock pistols. I use colt SMG lowers.

I like the look of a straight mag vs the swept back look to the glock mags.

The only 100% reliable lbho is colt smg mag lowers. (No matter what the manufactures say.....especially with 10 rd mags glock lbho shit is finicky at best)

These are my preferences. After that. Your choice.

 

[STS556]

Thanks togmaster for the lesson on the 9mm. Its not much different than a 5.56 AR.

 

[STS556]

Common does not matter.

If you have glock pistols, maybe glock is the way to go.

I run glock pistols. I use colt SMG lowers.

I like the look of a straight mag vs the swept back look to the glock mags.

The only 100% reliable lbho is colt smg mag lowers. (No matter what the manufactures say.....especially with 10 rd mags glock lbho shit is finicky at best)

These are my preferences. After that. Your choice.

I have also learned from others that the Colt is a much better platform to build on. The Colt it is.

 

[STS556]

As far a ammo specs go, I am not too sure what to use. It seems like 9mm Luger in either 115 or 124 grain. Any other specs like +P or parabellum I have no clue about. Any opinions on what to use?

 

[Marine Cpl]

As far a ammo specs go, I am not too sure what to use. It seems like 9mm Luger in either 115 or 124 grain. Any other specs like +P or parabellum I have no clue about. Any opinions on what to use?

I've shot all 9mm grains along with +P and +P+ with no issues whatsoever out of my Lone Wolf G9.

 

[togmaster]

As far a ammo specs go, I am not too sure what to use. It seems like 9mm Luger in either 115 or 124 grain. Any other specs like +P or parabellum I have no clue about. Any opinions on what to use?

Whatever is cheapest.

 

[STS556]

So in other words, any 9mm ammo will do.

 

[STS556]

Resurrecting an old thread.

I have been collecting parts here and there for this build. Over the winter when there is nothing to do I will get going full speed on this.

I have a question for Bullet Guy or anybody else who would know. I have a few of the special edition Bullet Guy lowers and I am using the NYGF lower for the 9mm build with a Colt magwell block. The lowers have a threaded pin ti install the bolt catch instead of a roll pin. I know the 9mm needs a special bolt catch. Anyone know if the 9mm bolt catch will work with the threaded pin?

 

[ArmedCorgi]

Resurrecting an old thread.

I have been collecting parts here and there for this build. Over the winter when there is nothing to do I will get going full speed on this.

I have a question for Bullet Guy or anybody else who would know. I have a few of the special edition Bullet Guy lowers and I am using the NYGF lower for the 9mm build with a Colt magwell block. The lowers have a threaded pin ti install the bolt catch instead of a roll pin. I know the 9mm needs a special bolt catch. Anyone know if the 9mm bolt catch will work with the threaded pin?

I'd say if the conversion kit you have is meant to work with a standard AR lower, then yes it should work fine.

 

[togmaster]

You need a 9mm bolt but a standard bolt catch will work.

 

[STS556]

Thanks guys.

From what I have read, not all bolts hold open on the ladt round. I just need to research which bolt will hold open.

 

[ArmedCorgi]

Thanks guys.

From what I have read, not all bolts hold open on the ladt round. I just need to research which bolt will hold open.

It's also sometimes the magazine you have in. Not only that but some won't fit in your upper and cycle with the bolt catch in. I went through that with my build. @Bullet Guy has a bolt that will work with a bolt catch.