Severe drag marks on bottom from hammer. hammer is ok. - FailZero M16/M4 Bolt Carrier Group (BCG) w/ Hammer

I bought one of these around 10 years ago directly from the company. Over 10K rounds and never an issue. This one, after 150 rounds, the gun ran worse. Thought it was a buffer tube problem. Running it slow, it fired great. Rapid fire it seemed the gun was sluggish and it wouldn’t load the last round in 3 different mags. Like it literally was bogging down. Went home and took the gun apart for cleaning and inspection. The bottom of this BCG has really sharp edges where it rides and there was a serious rub mark from the hammer that was gouged into the BCG. I mean I could file my fingernails from that rub mark. So I checked the hammer. Smooth as glass. It’s a Geissele, duh. So why did that hammer leave such a mark? Has to be the material of the BCG. Again, the hammer is smooth as glass. Bought a Sharps Rifle Company XPB and ran another 150 rounds through the gun today and it ran perfectly. Can’t even tell it was fired and no rub marks on the bottom from the hammer. Really a night and day difference. Quality control has slipped tremendously and I can only hope it was a bad batch. The quality of the NiB coating is no where near the quality on my first one. Don’t think I’ll be buying anymore until FailZero can prove they have fixed the problem. And I know you can buy these with or without their coated hammer. My last one, I never used the coated hammer either and again, never had a problem with that one.