yep, too slow. Ain't much that you can't do with 74-76 gr of 22 and a 180 in a 300 winnie. If your rifle don't shoot that load, it's probably the rifle. I've used Sierra prohunters, NP's, and Hornady SP's. They all shoot in the 300's I have had.
absolutely. If a nice stiff load of RL-22 won't shoot 180gr bullets in your 300 Mag it's probably something wrong with the rifle.
Just don't develope the load in zero degree temps and then go hunt in the desert at 110deg.
.....................DJ