Sounds like the magazine is failing to turn loose of the round being fed, quite soon enough. This could be several things but is fairly common with short straight sided calibers. It's hard to say exactly what to look for but see if you can watch the round jam. Deburr the feed lips on the magazine box and make sure the barrel is deburred.. If don't remove metal willy-nilly. It is possible (fairly easy) to cause worse feeding.. First smooth and deburr. If the round continues to bind, color a roung black with a majic marker and feed it thru a few times. Watch where it's being marked at the time it binds. If you feel uncomfortable take it to a smith. Feeding problems can be a bear but magazine boxes can be replaced..