hodgdon doesn't recomend it for lighter than 200 grain bullets. You'll never get enough of it in the case to get a 168 up to speed.....I don't think you could get a 168 up to speed with a weatherby 300.
Kraky: That's Hogwash. They list the powder suitable all the way down to 7mm mag. the largest bullet I have seen with the 7 is the 180 which I shoot at 2850 to 2900 w/ retumbo so for sure it will work in a 300 wm.
I agree with Kraky. I use 81 grains of H-1000 and 180 grain bullets and it is a very consistent load, but R-22 and H-4831 will produce a higher velocity and Retumbo is slower than H-1000...........