Robie,

I have a custom built .308 Norma Mag (for all intents ballsitcially a .300 Win Mag). It has a 24" Douglas barrel and it gets 3,100 to 3,150fps with 180gr Hornady bullets. I'm pleased with that but I wouldn't cut it any shorter, or I'd end up with a 30-06.

Cheers & God bless,
Magnum308