Trying to load fir a buddy's 7mm weatherby in a weatherby rifle. Having some serious trouble getting it to shoot. Using the 150 eld-x and retumbo on a suggestion and only got 2640 fps.. thats way way too slow. Bergers wouldn't shoot and I wanna stick with 150 eld-x. Thinking of trying R22 or imr 7828. What do u guys think I should try?