Bottom line: The .300 RUM is way too much gun for deer. I base this on the fact that nobody can shoot one from the most accurate position, which is prone, without the scope absolutely destroying the flesh and bone above the eye. And if you can' t shoot the gun from the most accurate position, it isn' t the most accurate gun. Period. More than half of the 29 big game animals I' ve killed were shot from the prone position, but those I' ve killed with both the .300 Wby and the .338 Win Mags could not be taken from that position. Therefore, the 7mm-08 has more effective range than either.