What comes to mind is:
-AMT Hardballer. Bought it in the late 70s. It never did run right.
-Early S&W M25 in .45 Colt. Would not stabilize any bullet I tried to put through it. Keyholed targets every time.
-PTR 91. Jam-o-matic. Never did get a full mag to run through it.
There may be more but these were the real stinkers.
FPD ret., USN ret., NRA Lifer
Never underestimate the power of stupid people in large groups.