ive seen that 399weatherby commercial, maybe nows the time...

have a .340wby, love it.

surprised at the 1 post of a .300wby kicking more than a .300 RUM.
either way its weatherby's most famous cartridge probably.
was probably the 1st magnum .300, I believe the .300 win mag came out after wby's release....
certainly a great round. if you want to split hairs on the win mag, or RUM, or .30-378 etc...