Savage,

I built a double rifle in calibre .450 #2 Nitro Express, about 10 years ago, using Douglas Supreme barrels, with a twist rate of 14". The rifle is regulated with 500 grain Hornady RNSP bullets but it shoots the 350 grain Hornady RNSP, designed for the .45-70, to the same point of impact. Last September I put a right and a left on the shoulder of a big bull Sable at 208 yards with that load. That's how well it shoots in a 14" twist.

Best,
Ron Vella.