The worst was a winchester 250 leveraction, the first one I tried was my uncles, never hit anything with it when hunting I couldnt even see where missed went, barrel seemd straight and the sights wer'nt loose , I figured I was a lousey shot, shot My Win 9422 it was a death ray in comparrison.
14 years later on I was given a box of parts Win 250 and bought some parts after searching 2 years and got it working, just like my uncles .22 I couldent even see the misses, they must of been way off. I sold it at a yard sale for $25 far less than what I had in it for parts.
The only other bad gun was a very worn Western Auto marlin model 30as 30-30win it was so worn it shot patterns, couldent hit a coffee can at 60 yards off a rest.
I have a Winchester 1400 12ga and havent had any problems with it, releasing the bolt is wicked nasty (thumb Gillotene)