Bill,
Is this a S&W? On some of the older S&W's the frame lug is a separate piece from the frame. Not only can it be replaced, but it can be adjusted as well.
My pimped 1917 had that problem. I opened up the side plate and pushed it out a 32nd or 16th of an inch. Lock tight into place. Problem solved.
If that had not worked, I could have purchased a replacement.
Not sure this advice goes across the entire S&W product line, but it worked on my 1917.