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Bart B. · January 21, 2015, 09:26 PM

I think 100 yards is too close to use the OCW load development method. OCW methods are best past 300 yards.

About 1.8 grains difference with IMR4350 charge weights under 165-gr. bullets makes about a 100 fps change in muzzle velocity in the 2800 to 2900 fps range. Drop difference at 100 yards between them is about 3/16ths inch. To resolve that much difference on paper targets, each load has to shoot about half that much (3/32nds inch), at worst, 100 yards down range.

You can shoot four or five 3-shot groups at 100 yards with the same .30-06 load and their centers may well be scattered about a 1 inch area; they won't all be exactly at the same place. 3-shot groups at any range have little statistical significance, in my opinion.

I've reloaded 165's in two .30-06 factory sporting rifles and never saw any significant change in accuracy over a 2 grain spread in charge weight of several powders, including IMR4350, at ranges up to 300 yards. So, I suggest you load 10 rounds each in 1 grain increments of 56, 57 and 58 grains (pretty close to maximum, I think), then shoot them in 10-shot groups at 100 yards. Use the load you think shoots the best.

You can adjust your zero anywhere away from the point of aim. 1 to 2 inches high at 100 yards is good.

January 21, 2015, 09:26 PM	#2
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	I think 100 yards is too close to use the OCW load development method. OCW methods are best past 300 yards. About 1.8 grains difference with IMR4350 charge weights under 165-gr. bullets makes about a 100 fps change in muzzle velocity in the 2800 to 2900 fps range. Drop difference at 100 yards between them is about 3/16ths inch. To resolve that much difference on paper targets, each load has to shoot about half that much (3/32nds inch), at worst, 100 yards down range. You can shoot four or five 3-shot groups at 100 yards with the same .30-06 load and their centers may well be scattered about a 1 inch area; they won't all be exactly at the same place. 3-shot groups at any range have little statistical significance, in my opinion. I've reloaded 165's in two .30-06 factory sporting rifles and never saw any significant change in accuracy over a 2 grain spread in charge weight of several powders, including IMR4350, at ranges up to 300 yards. So, I suggest you load 10 rounds each in 1 grain increments of 56, 57 and 58 grains (pretty close to maximum, I think), then shoot them in 10-shot groups at 100 yards. Use the load you think shoots the best. You can adjust your zero anywhere away from the point of aim. 1 to 2 inches high at 100 yards is good. Last edited by Bart B.; January 21, 2015 at 09:45 PM.