I have a Sig 556 Swat and I am trying to install a Magpul enhanced trigger guard. The problem is the rear of the trigger guard fits fine and the roll pin goes in no problem. The problem is that the front of the trigger guard where the set screw goes in is not right. Rather, the set screw supplied by Magpul screws into the trigger guard fine but is barely too big in diameter for the receiver portion of the Sig. Any thoughts or suggestions? I called Magpul and they say it is a standard AR 1/8" set screw so they are unable to help. Figured I would turn to you folks as I have seen several 556's on the forums that have this trigger guard installed. Thanks in advance for the help.