.300 WSM or .300 Win Mag

[smchop]

If doing a WSM and going 7mm DO NOT do a 7WSM, go 7/300WSM as it's a simple neck down from 300 WSM brass. The original 7WSM has a longer shoulder length and brass is nearly unobtainable and thereby needs to be made and fire formed from 300 WSM (or 270 or 325) whereas the 7/300, you just neck it down.

WSM's throated for a long action don't give up any performance to the WinMag/RemMag cases.

For example I have 2 rifles chambered in 7/300 WSM, my hunting rifle has a 26" barrel and I run 162's out of it at 3100 fps and change without breaking a sweat (I've run them up to 3200 but it's at the pressure limits for sure. (this one is a short action)

My ELR rig is the same chambering on a long action and throated to run 180 class bullets at full case capacity. It has a 30" barrel and runs 180 ELDM's with no pressure issues at 3150 fps. At our elevation it delivers a 180 ELDM at 2229 fps and 1985 ft/lbs @ 1000 yards. It goes transonic at 2550 yards. The only thing in a 30 cal and a standard magnum action that comes close is a 30 Nosler and it's not quite there.

For ballistics and energy on target the big 7's are very tough to beat. That said a 300 Norma is pretty impressive as well, but you're playing with Lapua mag actions in that case.

One thing I never understood was building a WSM or SAUM and having to use a long action. Whats the point? I mean I get it and why but you just cancelled out the whole reasons of the benefits of that cartridge. I agree on the Norma, but barrel life is still a concern for me.

If you plan on shooting 230 grain 30 cal then it’s time to pull your head out of forth point of contact and just build a 338 something

Why not build a .338 Win Mag that shoots the heavies that can mimic the lighter rounds of a .338 Lapua? I don't have the expense of a Lapua, a specific can for a Lapua, an action dedicated to a Lapua, but can mimic the ballistics. I agree the Lapua is a great round, I had one.