Re: max load for 6.5-284 norma
My LRH in 6.5x284 using H4831sc, 140Berger VLD's, Lapua brass, Fed210M's, bullet seated .075" off the lands is 53gr. This is a max load that gives slight flattening of the primers, very slight stiffness in bolt lift. The velocity runs 2934FPS and gives .25-.4MOA, and is my standard load. I get another accuracy/ES node at 51.5 gr, with velocity about 2875 FPS. I get stiffer bolt lift at 53.5gr. For higher velocity and lower pressure I prefer Retumbo. Using my standard Retumbo load, 57.5 gr, Fed215 primers, I get 2970FPS, no pressure signs, same accuracy. I can load as much as 59 gr of Retumbo for 3020 FPS with slight flattening of primers, slightly stiff bolt lift, but the accuracy falls off slightly, and ES increases. Both loads are effected by primer selection. A Fed 210 vs 215 magnum is about 40FPS higher resulting in powder charge being backed off about 1 gr to get the same velocity. I generally have used the 215's with Retumbo, and 210's with H4831sc. My ES for both powders run 8-12FPS, and accuracy at .25-.4 MOA. I get just about identical results in my Cooper using equivalent loads except for velocity due to the 26" barrel, about 20FPS higher. I should note that my loads have been checked for pressure and velocity between 20 and 80 degree temps. I would recommend starting loads that are backed off a grain or two from the loads shown to due to possible chamber/barrel differences between rifles.
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