338 WSM-any improvement over 338WM?

30cal user

Sergeant
Full Member
Minuteman
Dec 20, 2008
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SE, LA
Any reason to think 338WSM would get better velocity than a 338WM with 250 grain Scenar or VLD??

just curious

i did a google search and came up empty...
 

BobinNC

Gunny Sergeant
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Jan 31, 2009
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Goldsboro, NC
Re: 338 WSM-any improvement over 338WM?

The 300 wsm has a case capacity of 80.4 grains of water. The 338 Win Mag has a case capacity of 86 grains. A 338 WSM wildcat might pickup 2 grains by opening it up to 338. but that would still leave it short, by about 5%. All things being equal a 338 win mag should develop about 2-2.5% more velocity or about 60 to 80 fps at equal pressures.

Now if the 338 wsm is chambered in a typical short action, I would expect an even greater velocity difference, as match 338 bullets are fairly longish, eating up case volume.

So no, that dog won't hunt.......