What would be the specs. for the above cartridge? I was thinking 300 W.S.M. brass opened to 338 diam. I want to covert my 300 W.S.M. Winchester. Or should I make a 325 W.S.M. (since the 325 in NOT a wildcat cartridge it might be easier to get dies) Any ideas?

There are no standardized specs on a .338 WSM cartridge, and I don't see any good reason to go with that chambering over the old .338 Win. Mag., which will do more things better in the first place.

Personally, if I wanted a medium-bore based on the WSM case, I'd go with the .325 WSM and call it good.

AD

Did Bob338 comment on some thread as he has extensive experiance with that cartridge?

Unless your 300 WSM is a unique rifle I would just keep it as a back up if it shoots and if it does not then sell it and buy a new magnum.

As Allen suggested the 325 WSM is close enough.

What's wrong with the 300 WSM?

Savage99
The rifle just won't shoot. I have restocked the rifle, installed aluminum pillars and glass bedded the action. I installed a Jewell trigger and a David Tubbs firing pin and spring. It has a Shilen barrel with a 1-10 twist.I must have tried 10 different loads and all I get is 2 and 3 inch groups @100 yards. And that's with select loads. I would sell the rifle but I don't want to stick anyone with this lemon. I do believe that a new barrel and "trueing" the action will help.

What Makes A Rifle In-Accurate?
Possible Cause
Possible Correction

Cracked Stock
Glass Bed

Bent Guard Screws
New Screws

Bolt Stop Touching Stock
Relieve Area

Damaged Or Burned Out Crown
Re-Crown

Burned Out or damaged Throat
Set Barrel Back & Re-Cut Throat

Damged Rifle Barrel (worn-out, rust, etc...)
New Barrel

Stock Warped
Glass Bed & Float Barrel

Ring In Barrel
Cut & Crown or New Barrel

Bent Barrel
New Barrel

Excessive Fouling
Clean Barrel

Bad Scope
Factory Repair or New Scope

Loose Sights
Tighten Sights

Loose Scope Base & Rings
Tighten Base & Rings

Recoil Lag Not Making Proper Contact
Glass Bed

Also sometimes the action is "bedded" on the magazine box or the stock screws are bottoming out and are not really holding the action tight.

The above is a short list of the usual suspects. Right now I am into kitchen sink recrowns. (Allen Day roles eyes).

Just spin a 8mm bullet with compound on it on your crown. If that does not work then really rip it out with that tappered round stone that comes with a Dremel tool. Don't use the Dremel tool with the power on!. Just turn the chuck by hand a few turns.

This works very well for me. If you screw it up then take it to a smith. They only charge $50 anyway and it's the same price to fix what you did so you may as well try it.

What kind of action is it?

Take a look over at the shortmag site:

shortmags.org

You should find some info about the .338 wsm on the wildcat forums.

Regards,
Terry

Hglass, what make is it? It's not by chance one of the M70's with and oval chamber is it?
Those groups suck! Who did the rebarrel? Was the action trued at the time? Unless you just want a bigger bore, you might want to get your barrel turned back and rechambered, instead of buying a new barrel, dies, etc.
That said, I definitely see the appeal of a big-bore WSM. Hell, I want one in 35....