I've never owned a 300WM, but have owned a 30-338, aka 308 Norma, one of my favorite bullets was the 180 grain Hornady FB. I used H4350, I don't remember the exact amount. What I did was add powder until I got a little over 3000fps, then called it good because it shot great. You can get the same performance out of your 300WM. If you can't get one shot bang flops on deer with that kind of power, you'll need a better excuse than your bullet choice.
