blems
I bought a fairly large quantity (1000) of 9mm/115RN plated "blems" from a firm (PM me if your want details), one of the more stupid things I've done. I saved maybe $20.00. Load a bunch, nearly all of them. Took them to a match, couldn't hit a dang thing, embarrassing. And stupid. Should have tested them for accuracy.
Few days later, put the pistol on sandbags on a bench. At 20 yds, I could not keep them on a pie plate, and many that hit were tumbling. At 10 yds I could keep them on the plate, but most tumbled. Went home and mic'd a the ones left I had not loaded, they were mostly undersize.
By slowing them WAY down, I could get most of the tumbling eliminated, but the velocity/energy was so low, the slide would not fully cycle. My Glocks became single shot pistols. Relegated the whole batch to single practice from the holster and for failure drills.
MORAL.....if you buy blems, buy a small quantity first.