I was at the gun shop about two month ago when this guy comes in there with a Springfield Armory loaded & said he wanted to sell this piece of junk. he said some other things I had to leave because he was makeing me mad because of what he was sayng about the gun. any way I waited until he left & went back in there & ask Mike what was wrong with that guy. he said he bought it used & try to shoot it & no matter what it jam. I said that don't sound right . he said I know he said I try to work with the guy to try to fix it. the guy said no give me whatever you think it worth I don't care I don't want it any more. any way I went back about a week later & ask what was wrong with the gun. he said first I called Springfield Armory to see what year it was made they told him it was made in 1996 then he took it apart & found that the extractor was wore out he replaced it & the recoil spring because it felt weak to him took it to the range & it run fine he said it look like somebody a loaded round into the chamber & then slam the slide on the round causing the extractor to wear out. the moral of this story is if you buy a used & it don't run like it should take it to a gunsmith first. I know there are some gun you just can't fix but that used gun you bought might become the best gun you ever own.
Seems to me, with any gun purchase (new or used), you pull it apart, clean & inspect it.
Hell, it's amazing how many "problems" can be fixed with a thorough cleaning. Sorry, a bore snake is not a substitute for a proper cleaning now and again.