80% AR9 build questions

DJBrad

NES Member
Joined
Sep 16, 2014
Messages
15,843
Likes
40,872
Feedback: 2 / 0 / 0
I’m considering a build with a dedicated AR9 pattern 80% lower with an upper and 9mm bcg. Parts are pretty much all Grid Defense as I love their stuff.

What sort of buffer tube, spring, block, end plate, is needed for such a build? I’ve heard the spring should be blocked in the tube as the AR9 bcg relies on blowback?

Any thoughts?
 
The usual LPKs for blowback AR9s come with a heavy buffer.
So that standard AR15 CMMG lpk kit (with the awesome trigger) would not be appropriate for this build? Of course I’m not aware of any lpk that contains the buffer. Unless you’re speaking of an actually build kit?
 
This is all you need:

1) Any basic LPK. Any standard ar15 trigger will work on a 9mm
2) 7.5.ounce kaw valley buffer
3) Sprinco blue spring
4) Kaw valley bolt
 
62F2C6E5-FB00-4CE7-BF05-586E948C6ECD.jpeg No it’ll shorten the stroke in a normal carbine setup. The bolt only has to travel far enough the clear the catch. Remember an ar9 bolt is not as long as a traditional ar15 bcg. Ar15 has the bolt protruding from the carrier. On the ar9 the bolt is milled in to the carrier. So the ar9 bolt requires less room/ travel to do its job.
 
Last edited:
Back
Top Bottom