Bad batch or bad qc? - Strike Industries Extended Latch AR Charging Handle

I love these, but the last couple I have ordered(from here as well as other places) have not run smoothly like the ones I already owned do. When I go to share my rifles, it's almost like I'm running a file down it, or like it's full of sand. It's hard to describe. When I put in my older SI charging handles the action runs smooth. When I put the new charging handles in my rifles that had the old ones, it runs just like I stated above, like it's scraping or filing against something. I also notice that when I take the new ones out, the paint is wore off in about the same place on all of them, but this never happened on my older ones. And the older ones have seen alot of use. My honestly opinion is to just get the strike industries extended charging handle latch instead and just replace that part on your milspec charging handles.