270, I had the Mod 16 WW in a 300WSM a few years back. One of the hardest kicking little rifles I've ever shot. That sob kicked harder than any 300 Mag I've ever owned. Even kicked harder than my turkey guns! Anyway, I couldn't find a recoil pad that fit that particular stock so I printed off the diagrams from Sims sight and placed the stock on each one. The only one that fit right was the TC Omega pad, but it had to be altered. It has a raised portion that fits inside the TC stock and one of the holes didn't line up. I sanded the raised part off, drilled a new hole, and it fit just fine. That pad was a big help on that little rifle and made it much more pleasant to shoot.
That said, I wouldn't go through that trouble, just buy a prefit Kick-Eez pad. Model 118 works on the syn model 16/116 stocks.
http://www.kickeezproducts.com/pre-fit-recoil-pads.phpGood Luck
Reloader7RM