48th, whatmags were you loading it up with? I too have a .300 Ultra Mag, andretumbo works awesome in it. Withremington brass, fed 215 primer and101 grains of retumbobehind a 180 Nosler Accubond, I get 3400 f/s and 1"-1.5" groups depending upon the day and the shooter (me). I know thatI could get betteraccuracywith different loadsbut I'll wait until my guns gets a makeover for that.