I've got a 444 & plan on using factory loads from Hornady with their 265 grain bullets. Only problem is that I like to eat elk. So usually the 30/06 ends up with me on the mtn.
I really would like to try it on a big ole black bear.
Years ago, I felt as you. That ol' ought six really maintains your confidence. But after many years of elk hunting, I realized that most of my elk were taken at under a hundred yards, so if that is your experience you really aren't being hampered by using a 150 yard rifle. The 265 grain Hornady bullet is a good one. Maybe if you use it on bear and are successful, you'll feel more confident using it on elk.
Take the plunge, man.
