Re: How to tighten up my group.
Reloader 19 is too fast for 300. For 180 grain bullet,start with 80 grain of H1000 and work your way up. I used Federal 215M primer exclusively with good result on H1000. Don't worry about the setting depth. Right now I'm developing load for my 300 Win Mag using Barnes 180 grain TSX. With 74 grain of IMR 7828, I was able to get velocity in excess of 3000 fps on my Model 70 Winchester Laredo. Accuracy is excellent. Goodluck.
To achieve the maximum possible accuracy, all variables must be remove or at least minimize.