I don't pay much attention to primer recommendations in reloading manuals. I have used them all, and have found over many years that I usually get my best resulkts with Federals - not always, but usually.

In addition, I routinely use Magnum primers (Federal 215's) in but two cartridges - the .416 Rigby and the .375 H&H Magnum. This is due to their relatiuvely large case capacities.

If I were loading any of the FULL-LENGTH Weatherby cases, (.300, .340, .375, .378/.460) I'd also use F215's in them. I have NOT found it necessary to use Mag. primers in '06-length or shorter magnum cases like the .300 Win. Mag., the .308 Norma, etc. However, with few exceptions, I have NOT shot a lot of these calibers in extremely cold weather, so PERHAPS a magnum primer would work better way below zero!