I think a 1:10 inch twist is way too fast for 180's out of a .300 WSM. Back when 30 caliber magnums were "the only way to go" for long range competition, 1:12 twist barrels were the best for 190 and 200 grain bullets. Spinning bullets too fast is one sure way to get fliers way out of your group when a bullet's unbalance is above average. 1:10 twists are for 220-gr. bullets from that cartridge.
I had a worn out Palma rifle barrel's back end cut off to make it 27 inches long then rechambered for .300 Win. Mag. It's 1:13 inch twist shot Sierra 180-gr. HPMK's into 2/3 MOA at 1000 yards with ease. Those bullets spun about 171,000 rpm leaving the barrel; just about perfect for that bullet.
If you'll only shoot 180's, a 1:13 (or maybe a 1:12, for milder loads) twist's hard to beat from a .300 WSM.