Wouldn’t run - Midwest Industries Enhanced Nitride Bolt Carrier Group (BCG)

Fit and finish were excellent, so I was disappointed when I couldn’t get it to run. Put 20 rounds through it in an existing rifle length platform, and it short stroked every round. Single loading would not lock back on an empty mag, and full mags would eject but not feed.

I tried to identify the problem before contacting OP, and found that the gas key port was oversized compared to other BCGs. I don’t have a set of pin gauges to get a measurement. The cause may have been something else entirely. Returned to OP, and am looking for another BCG.