So I have 2 KWA M4's same setup (with Cheetah MOSFETS) and on one the first I would say 10 bb's just kinda dribble out of the barrel when the trigger is pulled and after that they come out perfectly, however with the same mag, I tried it out of the other M4 and they shoot perfectly.
I am well and truly stumped as to why the first 10 rounds or so, just kinda dribble out and than it fires perfectly, and on the other M4 it shoots perfectly from the moment the trigger is pulled.
Magazine is a King Arm MidCap
M4's are KWA's