I agree I would get a little bigger then the 243. My cousin killed almost a 500 lb bear in wv about 10 years ago with a 6mm. But the muzzle was touching it between the eyes. The bear was in a rock cliff where the dogs bated it. A lot of the people in his bear hunting group uses lever factions in 30/30, 35 45/70 or Holstein smaller caliber. He manly uses a 480 ruger revoler now. He killed a 240lb bear with it this year.