Home Forums Hunting & Shooting Ask The Gunwriters OCTOBER: Ask Wayne van Zwoll Questions About "LOADS FOR THE LONG SHOT"

Hello Wayne - a question:

I'm reloading for my .257 Roberts, Mauser action, 24" barrel. 117-gr Hornady SP bullet, IMR 4350 powder, CCI large rifle primers, R-P brass, bullets loaded just short of the lands.

My Hornady manual says with 41 grains I should get 2800 fps, and with 42 grains 2860 or so.

My chronometer readings at the range say (average of 5 rounds per load): 41.0 gr - 2569 fps;

41.3 gr - 2604 fps;

41.6 gr - 2633 fps;

42.0 gr - 2670 fps.

Why are my readings so much lower than the books (both new and and an older Hornady manual) say I should be getting? I am not getting any signs of excessive pressure and I am .8 grain below the max load listed for +P loads in the newer manual.

Thanks! Tom