Re: My 300 RUM doesn't like 200 gr AB's, will it like 190 or 210 Bergers?
My 300RUM Sendero wouldn't shoot the ABs very well either. Finally found some 208gr AMAXs. With a quick load development(was going hunting with my brother in Wyoming the following week) I got it to keep .5 moa out to 1K. 94grs Retumbo, 215M primer, remington Brass. COL 3.65(max mag length). I might tweek it in the future when I get time, but it will be good for now. The AMAX worked great on the 174", 300+lbs Muley I got. Droped him like a rock.