DSA ZM4 A3 Upper Receiver; 20" Nitride FLuted Barrel, M4 Feed Ramps how is this barrel /upper holding up with care ,accuracy etc??
I have a 16" fluted 1:9 nitrided ZM4 upper from DSA. I mated it to an LMT S/A BCG. I’ve only got 1100 rounds of brown bear through it, but it’s run all of them like a champ.
As for accuracy, let me repeat, I run brown bear through it.