This is the brake I am wanting to put on it.
http://www.circle10ak.com/
I thought I knew for sure that the barrel length on my AMD was 12.5 inches, but after double checking on google, I see a lot of people saying it's 12". Still, I am pretty sure some folks got it wrong, but want to triple check.
Also, I don't know if this brake will fit. So if you can tell, and inform me, that would be great. Thank you.