Has anyone tried necking up a 300WSM for a 338 bullet? Any ideas if it is even worth it? Wouldn't it be pretty efficient?

I've got the dies!




Everyone including RCBS thought that the 338 WSM would be the next in line for production and RCBS jumped the gun and even made dies for them.
It turned out that the 338 WSM didn't acheive the hoped for velocities and was no real improvement over the 338-06. So they ended up going with the 325 WSM which IMHO is a fine round in and of itself.

Net answer is that it's been done but wasn't that great........................DJ

I smashed 7mmWSM cases into my 300WSM dies and the result works fine in my rifle with its .002-inch headspace. I use 'em for foulers because I have both brass and nickle-plated ones. Try your 338. Do it with gusto and tell us how it worked out...

With the wheel base length of 338 projectiles,I'd suggest you twist it with a 1:9 instead of the industry standard 1:10 twist.

I prefer the RSAUM case as it functions better in a short action.