Originally Posted by oldmodel
Has anybody got any experience with retumbo powder in the 300RUM? Looking at the loading data on the can it seems to give higher velocities than other powders for this cartridge. - Can one expect these veloctiies to be close to what is listed?
I tried Retumbo in my .300 Weatherby behind 200 grain lead and it wasn't too good velocity wise or accuracy. My friend uses it in his .300 RUM, and swears by it. I think he's using 180 grain lead.