I have a .300 Winchester built on a Borden Timberline Magnum action. The rifle is extremely accurate with every bullet I've tried and loves HOT loads. It has a 25" Fluted #4 Rock Barrel with a 11.25" Twist, Mcmillan Classic Edge stock and Wyatt long box. I've never tried, but according to Bergers twist calculator the 215's are out of the question and the 210's would be marginal. I live at 200' above sea level and hunt up to 4000'. Which bullet would serve me well for deer, elk and black bear? Shots inside 700 yards.