300 and 325 cases have the same length from the base to the origin of the shoulder (i think, I'll have to double check that one). We tested three Speer Hot-Cor Spitzers (150, 165, and 180 grains) plus the 165-grain Trophy Bonded Bear Claw, available as a component then.

For example, the standard 180-grain load of the .300 Winchester Magnum is 2960 fps, while many of the .300 WSM loads with the same bullet weight will run at 3000 fps or better. It is designed to stop the case against a corresponding rim in the chamber. We ping steel with a .300 WinMag at over a mile. Repeating Arms Company was the first major manufacturer to commercialize Lazzeroni's concept, followed shortly thereafter by Remingtonwith their "Short Action Ultr… What about using the .325 WSM case? You must log in or register to reply here. Long bullets intrude into its powder space, too.

You might short stroke it and fail to bring a new round into battery.

Or so goes the advertising hype. Using the base diameter of the common H&H belted case (presumably for ease of manufacturing) instead of that of the slightly larger Jeffery parent case, the .300 WSM has a slightly rebated rim. The U.S. Shooters have been complaining about the belt around the head of belted magnum cases for at least 30 years. The history of the .300 WSM is a sordid one, involving lawsuits and court cases; Rick Jamison had a huge part in the development of the design, yet without raking the muck, isn’t always credited for that work (the original name of the .300 WSM was to be the .300 JRW, standing for Jamison, Ruger and Winchester). Long, heavy bullets are one category in which you’d imagine the 300 WSM would fall behind the 300 Win.

This is not loaded ammunition. .308 to .338 is more easily achieved, but (325wsm/8mm) .323 to .338 is one pass thru the die, and I would think that would promote much better case life and ease you into wildcatting with a few less steps. ©2020 Outdoor Sportsman Group. Not even in an auto-loading Browning BAR. Personally, I don’t believe I can feel this difference, but many WSM lovers swear they do. But is that justified?

Hodgdon’s online data shows they broke 2,800 fps with a 200-grain bullet with several propellants that we were not able to get before the Speer Reloading Manual #14 had to go to press. Mag. However, maybe it should be a... Give a Gift   You are correct about the ever so slightly larger 7wsm case, however I think what skip just posted makes the most sense for necking up, 325wsm makes more sense. The 300 WSM, or Winchester Short Magnum, is magic. Mag, 300 Win. But a careful look at several handloading manuals reveals the 300 WSM hanging right with its longer legged cousin when pushing 190- to 210-grain bullets.

If you don't lump yourself into the extremely knowledgeable category but have something to say by all means do so.