I don't think that an Improved 300 Rum will gain enough aditional powder space to make much of a difference. A 10 percent increase in powder capacity will give a 2 1/2 percent increase in velocity at the same pressure. The RUM case doesn't have much taper to begin with. You could install a longer magazine and seat the bullets out farther and gain a bit of capacity that way. That is what I did with a 338 laupa I had a detachable box mag installed that allows me to load to 3.885" COAL insted of 3.6"...
range it,check the wind, dial in correction, aim and only one shot
Last edited by jwp475; 05-03-2008 at 09:28 PM.