Overbore and kicks like a mule.
Best one is the .300 Win. Mag.
I'd do a 300 WSM over a 300 WM.
Nope.
NOPE II.
I really can't wrap my head around the "no belt" thing. My first mag rifle was a 300 WM @78-79 and have used 'belted' mags ever since.
I 'ain't never' had a single problem from a belted mag case.
Jerry