Is there any significant difference between a 300 win mag and the 300WSM??My boks do not show the newer cartridge..What do you load in 180gr ???

Thanks,

Mike

Judging by the more reliable posts here and elsewhere, 50-100fps in handloads and 'high velocity' factory ammo, almost nothing in standard velocity factory ammo.

About 1/4-1/2 lb lighter in like barrel lengths and contours for the WSM based on manufacturers published weights....negating any possible recoil advantages for the WSM due to less powder used.

All of that is irrelevant to most...you either like the WSM or you like the WinMag...in the field they are virtually interchangable!

I load 65 grains of H4350 (I think 1-2 more grains is safe, but accuracy suffered), WLRM, 2955fps, Nosler BT's, 2.95" OAL, .75-1" every time, YMMV!

The 300 WSM is a slightly improved version of a great cartridge. In factory loads the two are indistinguishable. If you handload you probably can get maybe 100fps more out of the 300 Win Mag.
The WSM is available in Short Action Rifles some of which are entirely new actions custom tailored to the WSM's. If you already have a 300 Win you may not need a 300 WSM. If you are buying new IMO the 300 WSM is the more modern and slightly superior of the two. It kicks slightly less,can be had in lighter, handier rifles and arguably is a little more accurate........DJ

While the cartridge case design of the 300 Win Mag and the 300WSM are quite different, the performance they provide is pretty much identical. Either cartridge will safely provide velocities in the neighborhood of 3050 fps with 180 grain bullets in a 24 inch barrel.

I just finished working up loads for a new Model 70 Winchester in the 300 WSM. I tried RL 19, RL 22, N560, and IMR 4831. I settled on a load of 68 grains of IMR 4831 behind a 180 grain Nosler Partition. This load provides a velocity average of 3052 fps and groups of an even inch at 100 yards.

This is exactly the same type of performance I have seen in several 300 Win Mag rifles I have tested. There are exceptions, I used to own a Remington 700 BDL in 300 Win Mag that would go a LOT faster, but like a fool, I sold it.

Hope this helps, R F