Bill, actually I DID have some trouble with the Sig. I tried them on my Colt and didn't have any trouble, but 2 problems on the Sig. ON the left side the grip sits about 1/16 off the frame. I can't budge the bushings to screw them in a little, although i only tried with a screwdriver and didn't get into anything else.
On the other side, one of the bushings kept unscrewing instead of the grip screw. I cured that by putting some blue loctite on the bushing, screwing it in, and leaving it for 2 days. Then I could get it off ok.
The only other problem I know of is whether your gun uses standard or thin grips...the bushings are spaced a little differently. THat is easy enough to look up online.
All that aside, I like the "grip" the grips give you.