i've loaded the .300 Win Mag for 40 years. Presently i load for my Ruger M77 anda Mathieuwith a28" barrel.IMR 4350 or IMR 4831 are much better powders forthe .300 Win. Mag.


"I haven't found that to be the case with the cartridges that I have loaded with both cases.With the 7mmremmag,30-06,300winmag and 338winmag,the winchester cases have slightly more volume and produce less velocity than remington cases using the same load."

Ditto for me. i often weigh and segregate my.308 and .30-06 cases.In .30-06, Winchester casesare alwayslighter than Remington by about ten grains. i alwaysuse Winchester cases for my accuracy loads.One of my .30-06 rifles likesa Winchester case and primer, ahuge quantity of IMR 3031 anda Sierra 150 grain BTSP bullet.Have put together some very accurate loads by weighing and detailing my cases.