AR-9 build question

[Rob]

Two questions for those who have done an AR-9 pistol build

1.  If one is building an AR-9 and has a lower that takes Glock Mags, will any pre-built upper work, or do you need to find one that will work with a glock mag lower?
2.  These have blowback actions - is a standard AR buffer and buffer spring usable, or do you need a setup specific for blowback setups?

Any other "gotchas"?

[hunter399]

You better build it FAST
Cause with a Biden win
We will all be felons
The assult weapons Ban will be put back in place from 94.
No more online sales for ammunition and firearms.
No 80 lowers
And most of the country will start to feel the same gun laws as Washington State.

[jay.sharkbait]

You better build it FAST
Cause with a Biden win
We will all be felons
The assult weapons Ban will be put back in place from 94.
No more online sales for ammunition and firearms.
No 80 lowers
And most of the country will start to feel the same gun laws as Washington State.

Lol

[hunter399]

Sorry Rob didn't mean to thread jack.
I've never built one but do have friends that have.
And can ask around for ya ,and might be able to chime in with some answers later on.
Or maybe someone will answer before me.

[Rob]

Appreciate it!

Been poking around on line as time allows too - will report back if I figure out (for anyone who is following)

[Evil_EdwardO]

Two questions for those who have done an AR-9 pistol build

1.  If one is building an AR-9 and has a lower that takes Glock Mags, will any pre-built upper work, or do you need to find one that will work with a glock mag lower?
2.  These have blowback actions - is a standard AR buffer and buffer spring usable, or do you need a setup specific for blowback setups?

Any other "gotchas"?

I just got done building one but a PCC not a pistol.

1. It's the BCG that needs to be compatible from what I researched. Supposedly, the Colt BCG will work with Glock mags also but not the other way around.

2. They say you need a heavier buffer but I have seen people that have used a regular carbine buffer and spring with no problems.

As I said, mine was built as a PCC but I wanted to use a rifle tube to put a wooden stock on it. I used a 308 spring and buffer in mine and have had no problems at all.

3. What I found out is that you need to get a dedicated AR-9 trigger. I bought a Rise 140 trigger for mine and it said it was good for AR-15,AR-10, and AR-9. The third time I shot it, it started shooting 2-3 bursts every now and then. Don't get a trigger that lists the whole gambit of AR's, get one that is only for AR-9. With the blowback, the other triggers don't have a long enough delay so the hammer doesn't reset/lock back all the way which causes it to burst shoot.

For me, the trigger issue was my only hiccup. Will be buying a dedicated AR-9 trigger pretty soon.

 

[Rob]

First...  very good looking rifle!

Thanks for the info.  I found this snippet at the following website:  https://calgunandprep.com/gun-stuff/the-ultimate-ar-9mm-build-guide/

What about the Bolt Carrier Group?

The BCG is another component to pay attention to.  Besides the obvious difference in looks, you need to make sure your BCG will work with your lower.  There is a BCG that is specific for Colt mags, as well as one specific for Glock

This is the BCG that came with my upper. It is compatible with both mag styles and standard AR15 FCGs.
mags.  Beyond the magazine type compatibility, you also want to make sure that the BCG is ramped to be used with a standard 5.56 AR 15 trigger.  If it’s not, then you will need a special FCG which as we all know means extra cost for your build.  The good news here is that most 9mm BCGs are whats called a hybrid BCG meaning it will work with both style mags as well standard AR 15 trigger groups, just be sure to check before spending your hard earned cash.

This would seem to support what you found as well



 

[Fl0und3rz]

Tag along. Good luck with your build.

[konradcountry]

Check out the Odin works adjustable buffer, it's really easy to change.

I wouldn't go smaller than 7 or 8 on the handguard.