Is there a size difference between older P-226 grip screws and new? If so, what are the sizes of each?
thanks

There are two head size thickness on screws that fit the P-226. I'm not sure if the issue is old versus new or Sig wood grips versus plastic.

I ask the question, as I gave a friend (with an older P-226) a grip screw to replace one he had lost. All of my Sigs and parts are for newer Sigs and the grip screw was too large.

The issue is the thread size of the screw, not the size of the screw head.
thanks

According to TGS, the older style 226's use a screw with a shank diamiter of .115 while the newer guns use .153

That sounds like the small shank old style grip screws.