If you are refering to TC Contenders, this is more common than you think. The problem is not the frame but the barrel. What I refer to as the locking wedge, is not clearing the bottom of the frame. It's not a hard fix and have had to do about three, in the past. If you will do a search in here, you will see quite a few posts on this particular problem. In one past post, it is suggested that you send it in to the factory and they will make the fix for free. From what you described, it will take more than just a little honing. If indeed you are having a problems with a Contender, get back to us and do a search past posts. ......
Be Safe !!!