Does anyone out there know if you can re-chamber a standard 308 into a 300wsm? Bolt face size, OAL,...etc.

thanks mvm

Open the bolt-face, install a Sako-extractor, set the barrel back a thread or two you're ready to go.

Pshooter,
Don't listen to DB he stole Janet Reno out of my dog house and is hiding her in hes boudwah!!

Besides thats a good way to ruin a perfectly good .308.....

------------------
Ray Atkinson

ray@atkinsonhunting.com
atkinsonhunting.com

Maybe 30-284?

Tom

Converting an existing bolt-gun in .308 Win. to .300 WSM is an exercise in reverse-economy.

Rechambering is just part of the conversion process. Yes the feed rails and bolt face have to be altered as well, but then we get to the expensive, tricky part. The extractor with have to be either altered or replaced, and the existing .308-size magazine box, magazine follower, and magazine spring will have to be replaced as well - not only to achieve a three-round magazine capacity, but to achieve the correct stack angle for the .300 WSM cartridge. A .308 box and a proper .300 WSM box are not even closely related, and you cannot skate by with the existing magazine system. It won't work.

The best, most practical, and cheapest (by far!) solution is to trade your .308 in on a factory-original rifle in .300 WSM. The action and magazine system will be correct from the get-go, and you can always install a premium barrel if you need to, rebarrel to .270 or 7mm WSM later if you want to, etc - anything that's compatible with WSM-based cartridges. That action is timeless......

AD

Beg to disagree with Allen. I've converted a 308 short action SS M70 to WSM. All that was necessary was to widen the bolt face .010", no change of extractor and nothing to the feed rails. The magazine box and follower need to be altered. I just purchased the USRAC follower and altered the top of the magazine box to remove the lips by straightening them and making the box sides perfectly parallel all the way to the top. You can purchase the box for about $30 if preferred.

The WSM reamer will clean the 308 chamber.

Hi Bob... Isn't the head( of the case) for a WSM about .553 and a .308 about .435?

Wow that was fast. Don't you guys have a life
As usual you guys have given me exactly what I need to know. The 308 is in a bolt pistol and they are fixing to offer it in a 300wsm this spring. I think I will just buy the complete gun and be done with it! Besides, my 308 works, and the 300wsm hasn't proven anything to me yet!

Thanks abunch mvm

Sparticus~
Of course you're closer to right than I was. The bolt face does have to be opened whether .01" or .1". The base as best I recall without looking it up is .535" on the WSM, nearly same as base of the belted magnums. In any case the bolt face has to be opened appropriately. I didn't alter the extractor but if you want it to snap over the rim as when single feeding without going through magazine, you can grind that down enough to do so with a Dremel tool. I didn't and it extracts fine.

I did a 338 WSM on a 700 SF Sendaro that started out as a 7mm Rem Mag. Twisted the barrel off, put on a new barrel, reamed it, checked headspace, did a little work (very, very little) to the boltface, opened the feeder rails (got them wrong) and was at it. Also the magazine only holds 2. The gun's headed to CT to get the feederrails and the magazine fixed.

Having done this, I would say if you wanted to do a 308 to WSM conversion on a mauser bolt (i.e. Model 70 "claw") it's a slam dunk. Setback the barrel 2 threads at the most, ream, check headspace, open the boltface, open the feeder rails, take out a little spring and you're off.

My recommendation for a wildcat WSM (338, 358, 375, etc) buy a factory 300 WSM, take the barrel off, put on the new barrel (to the factory profile), ream, headspace and your off. No mods to the boltface, feeder rails or the magazine.

My $.02.

Regards,

Mark

I repeat, NOTHING needs to be done to feed rails or ramp on the M70 for the WSM. The magazine holds 3 rounds. My conversion also happens to have been to a 338 WSM from 308 via 338 Jamison. Its load development I posted back in September on HuntAmerica.

I can verify what Bob says as I now have his 308 barrel... thanks Bob!

The only thing that may make a difference (though Bob obviously hasn't found it so) is that the WSM Model 70 SA has an ejection port that is .250" longer than the "standard" Win 70 SA... probably a moot point.

Regardless, when the soon-to-be-released 338 WSM hits the street in SAAMI form, my Model 70 300 WSM will go to Pac-Nor to have a 22" (factory contour) 338 WSM barrel screwed on.

Brad

I thought it was simply a oversight. I hope I didn't affend you any. Mark