I have an unfired Colt 6920 sitting in my safe that I’m not doing anything with. I’m considering either getting an Adams Arms piston kit and modifying it or selling it and getting a BRN-180. I kinda lean towards the 180 and I love the recoil design, but hate the charging handle and how open the action is when the dust cover is open.

For those with hands on experience, which way would you go and why? What are the benefits of one over the other?

Don’t do that to Your colt, get a BRN-180, sig, PWS, or HK clone

I have both. In fact on a colt m4 diemco. I understand the concern about that opening. I have great accuracy from both. I have LPVO on the Colt and a PA 3x prism on my BRN-180. I don't have a shit ton thru either but way more thru the Colt upper.  I have noticed the op rod bending a little on my AA conversion. It still runs fine but it is a data point.

I really like the BRN-180 and I've shelved the AA/Colt with thoughts of selling it. Attached File


I also have the BRN-180s
Attached File

FPNI. I have a BRN180, MCX Rattler, PWS, AA kit, and SA kit. Either get the upper or modify another build with an SA piston kit or buy the brn180 upper. All of these are good and utilize a design based on stoners AR18 design so they will all feel kind of similar, except the PWS which is a long stroke system.

The BRN180 is very underrated

It’s different enough to be interesting
It’s common enough to be familiar

I really like the platform

I have a factory Adams Arms piston rifle. It's ok.  It runs fine, but there's just nothing special about it. Unsuppressed it runs clean, but I don't clean my guns very often anyway, so that's not really a benefit.  Suppressed it's still dirty from the back-pressure.  

I've had Adams Arms retrofit kits on uppers before.  They were ok too- but I also can't find any benefit to them.




I want a BRN-180.