sounds like they are working in 300rum's... I talked to a couple of guys who were using them and doing well. I see no reason the win can't spin then enough as it's only a bit slower. I decided to go another direction myself, but they should work just fine.
If you don't have a 10 twist or faster it won't work. Another thing is they have a really long bearing surface and need a long throat. The velocity is hard to get high because of bearing. I shot a lot a bunch of them in a 300 Weatherby IMP with a 10 twist and they shot good. 2800 FPS tops. You would probably be better with a 215 or 230 Berger. They also don't open well on game. Matt