Ok so when I firsr got my 20" bushmaster brand .450 upper I didnt have a dedicated lower set up for it yet.
I put a 1-8× scope on it and pinned it on a lower I originally had a 7.62x39 upper on it and sighted it in... It shot awesome. Just out of a leadsled on the tailgate if my truck I shot a few 3 shot 100yds groups you could cover with a nickel and that was only an 8x scope.
So fast forward to now Ive got a dedicated lower built for the gun, with a 3lbs drop in trigger compared to the standard milspec trigger in the other lower, I used a Armaspec SRS buffer system with the heaviest buffer they had for AR15s and put a Leupold VX-6 2-12× scope on the gun and it doesnt shoot as good now as it did with the other lower with crappier trigger and less scope magnification. The only real difference I can see would maybe be the buffer system... Went from a stock carbine weight buffer and spring to the heavier Armaspec SRS system.
Soo can the buffer system adversely affect accuracy or was I just lucky the first day out or not having a good day this most recent trip out???