In a bit of a quandary right now. Built this aero M5 upper with a blackhole weaponry 6.5 CM barrel and after torque the barrel nut to spec, I looked at the feed ramps and 1:theres basically no ramps, 2: what is left of a feed ramp doesnt mate with the barrel extension...... anyone have any insite? Are these feed ramps normal or aeros or did I get a dud?