Re: 300 RUM powder choice?
I have two 300 rum's and have had the best results with retumbo and h870 (no longer available but thunderbird in ariz. has t870 which is the same thing) I loaded 105grs of h870 for 3350' with a 195 gr homemade ballistic tipped 8s spitzer with rebated boattail, .590 b.c. (180 accubonds would make 3550') With my 700 rem. and 27"" lilja 10 twist I get 3225' with 95 grs of retumbo. This is a good hunting choice as retumbo is less temp sensitive than most powders. If you are into long range, this makes a difference.
I have tryed about every slow burning powder available and 870 will always give top velocity! Good luck.........Rich