kielwhite
Well-Known Member
300 RUM!
Until you get up to the Lapua sized case it's pretty hard to shoot out any of the .30 cal's unless you just abuse them to death running them hot and keeping on shooting.300 Weatherby is much more efficient and is nicer on barrels. I think for the .30 Caliber magnums, 300 Weatherby is the furthest you can go before you get diminishing returns on performance. I have a Mark V that my father gave me. It does have a 30" Douglas barrel on it now. I shoot 168's at 3550 fps, 180-grain bullets at 3375 fps, and 210-grain bullets at 3150 fps. I use about 80 grains of powder or slightly less to achieve this. 300 RUM will do maybe like 25-50 fps more but at the cost of 20 more grains of powder. To me, it's not worth it. Others may feel differently. I still find it funny that a cartridge designed in 1944 is still one of the top dogs in performance to efficiency.
Still get 15-20 more rounds per lb of powder with virtually the same performance in the 300 Bee than the Ultra when reloading.Until you get up to the Lapua sized case it's pretty hard to shoot out any of the .30 cal's unless you just abuse them to death running them hot and keeping on shooting.
With reasonable care and use any of them is most likely going to last you a lifetime.
I didn't comment on powder consumption, only barrel life.Still get 15-20 more rounds per lb of powder with virtually the same performance in the 300 Bee than the Ultra when reloading.