Posted this earlier today on SigForum.
So after much forum research I have discovered that
1) Sig 229 Equinox takes a longer grip screw than a regular Sig 229.
2) The Sig 239 grip screws will, in fact, fit the Sig 229 Equinox wood grips.
3) Sig 239 grip screws, with shipping, average 3-4 dollars per screw (check it out!). The 229, of course, takes four screws. And
4) Sig 239 grip screws (never mind Equinox grip screws) are out of stock and on backorder in most of the English-speaking world.
Now the heresy: So, in pulling my hair out trying to get some grip screws for my Sig Equinox grips (I foolishly traded the original grips WITH the screws), the odd thought crossed my mind. "You don't suppose Ace Hardware would carry grip screws?? Nah." I scoffed. What the hey, it's a five minute trip to find out. Guess what? Yes and no. If you get a 4mm hex screw with a .70 pitch you can almost make it work. Take your standard 229 grip screw and line them up together. Add two threads to the longer Ace screw and saw it off. Now run a nut up and down the "new" grip screw or even a file after that if it is still rough. Smooth as silk. No mag catch. Not even a scratch. See attached pics. I suppose for the purist (and, honestly, I understand that too) it's not the same. However, in this economy paying two bucks (includes tax) instead of $16 dollars and NO WAIT seems worth the trade.