He means domestic made ammo is mild enough to use in the .318. It's that way because of an influx of old "J" bores many years ago and hasn't changed.

Hunt with Class and Classics

Religion: A founder of The Church of Spray and Pray

Acquit v. t. To render a judgment in a murder case in San Francisco... EQUAL, adj. As bad as something else. Ambrose Bierce “The Devil's Dictionary”