RE: need load help for 300 WBY 180 gr. Barnes TSX and 4350 powder
If you want to achieve max velocity out of the 300 WBY you need to buy some RL22, H1000, or RL25. Any of the 4350's burn at too fast a rate for the 300 Wby. I'm not saying you can't use it you will just have better results with a slower burning powder in a case the size of the Wby.