Being new to the .30 BR, I know that most use H4198 Extreme for powder; but, has anyone tried the old Reloder 7 (circa 1974)? I plan to try it with 115 gr. 10X and Knight 118 gr bullets. Both are made on .925 J-4 jackets. I have no idea of how much of this fast burning powder I should start with. Does anyone have any experience with it. Thanks, James Mock