I had a couple instances with PMC that while most likely isolated and just a bad lot, left me with a bad taste. When you shoot often, you can hear and feel a difference even if it barely even perceptible and I'm glad I listened to my gut and decided to pluck the round out of the chamber to check, same PMC ammo a few months apart, I pulled the charging handle on the AR back and the sound of the bolt going into battery and the feel was all off.
I plucked the cartridge out to find the projectile buried into the case neck moving freely up and down. Not sure if it would have damaged the gun or not, but I stopped buying those tan 200rd battle packs of PMC after that. I'm sure it's all fine and just as good as any other brand that has an occasional out of spec machine pumping out bad product or perhaps ammo packs getting abused in transit (dont think I carefully inspect ever cartridge going into a mag), but that's what I immediately think of when I see PMC.
Never had any kind of issue other than that, it's pretty dirty and not any more accurate than steel case Wolf or Tula imo. Shot tons of PMC 9mm and never had an issue except when I used 124gr, for some reason my Glocks would spit the PMC 124gr straight back into my face, same with Blazer brass 124gr so I just stick with 115 and don't have the BTF issue.