I think the 308 is a great choice. The 308 ballistics are actuallyvery goodin a 20 Inch barrel. You will only loose around 20 FPS per inch with the 308 and 300 yards would bedo-able especially at the altitudes you most likely hunt. I do not have any personal experience, but I would suspect the 308 would feed much better than the sharper shouldered, WSM in a lever gun.