257 Weatherby Mag

71 grains of RL25, FED 215, under a 115 Nosler Ballistic tip with C.O.L. of 3.300 inches gave me the best group. Didn't put it through the crony, but if my numbers are correct it should be just shy of 65000 psi and about 3400fps. This is out of a Mark V with 26 inch barrel. I just got it and have been building up some loads. This combo gave me a .73 inch group at 100 yards. The best group for a 115 Nosler partition was 1.2 inches with 70.5 grains of RL25, with COL of 3.270. I'm gonna try it again with a bit longer COL and see if I can dial it in a bit better. Those were the max loads that I tested out of 14 different bullet and powder combinations. Neither showed any sign of excessive pressures but both those loads should be at the max pressure according to manufacturer. The 71 grains should actually be about 1100 psi over manufacturers specs.
This is just my results...
CLINT
PS: Can't get the 75 grain Hornady V-Max to shoot worth a s**t!
 
used to have a MK V .257 loved to shoot coyotes with 90gr sierra hpbt
pushing them with norma MRP forget the exact load (70-71gr.?) flat and fast and makes coyotes do summersaults,:D hard on hides though
 
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