Sounds like the stud was bent down as the comb on the trap stocks are a lot higher. If the stud doesn't want to bend fairly easily use heat. I have one of the Browning repop's and put a trap stock on it. Had to really bend the stud to get it to fit. Now the comb is pretty high, but will have to refinish everything anyway as the stock is a 12 and the receiver a 20. I'll take the comb down so it fits me and make it all pretty again. That trap stock was what is causing your issue.