308 to 300 WSM

TMC · May 15, 2002, 07:34 PM

Does anyone know if its possible to rechamber .308 to .300 WSM? I know the rate of twist may not be ideal but it does vary from maker to maker.

Art Eatman · May 15, 2002, 08:33 PM

Dunno how much the rate of twist is different, unless the WSM is faster, favoring heavier bullets.

Biggest problem, probably, is the diameter of the case head. Quite a few articles in the gun rags, talking about both the twist and the dimensions...

Art.

Don Martin · May 15, 2002, 10:03 PM

Of course it's possible but it's not practical. You will end up with a rifle that has a marked over barrel, money spent on the bolt face and feed rails and bolt stop.

The twist of the most .308's is 1-12 and that's enough for at least a 180 gr bullet but the big thing is the money.

A typical used .308 bolt rifle may be worth $300 and a new .300 WSM costs about $610. You will have a hard time being able to sell a worked over .308 that's now a .300 WSM however.

Just sell the .308 and buy a .300 WSM. Better keep the .308 and buy a new .300 WSM!

TMC · May 15, 2002, 11:02 PM

Thanks for the info. I was not aware that the base of the case was a different size. Not worth doing.

bela · May 20, 2002, 09:12 AM

In Germany/Austria the legal max. pressure of .308 is 4150 bar, of 300 WMR is 4300 bar.
Thats a little difference.
If you ream the chamber you will weaken the barrel end...
I think it would be quite dangerous to do.

May 15, 2002, 07:34 PM	#1
TMC Member Join Date: November 7, 1998 Posts: 92	308 to 300 WSM Does anyone know if its possible to rechamber .308 to .300 WSM? I know the rate of twist may not be ideal but it does vary from maker to maker.

May 20, 2002, 09:12 AM	#5
bela Member Join Date: May 14, 2002 Location: Austria Posts: 89	308 -> 300 WMR In Germany/Austria the legal max. pressure of .308 is 4150 bar, of 300 WMR is 4300 bar. Thats a little difference. If you ream the chamber you will weaken the barrel end... I think it would be quite dangerous to do.

May 15, 2002, 08:33 PM	#2
Art Eatman Staff in Memoriam Join Date: November 13, 1998 Location: Terlingua, TX; Thomasville, GA Posts: 24,798	Dunno how much the rate of twist is different, unless the WSM is faster, favoring heavier bullets. Biggest problem, probably, is the diameter of the case head. Quite a few articles in the gun rags, talking about both the twist and the dimensions... Art.

May 15, 2002, 10:03 PM	#3
Don Martin Member Join Date: February 6, 2002 Posts: 52	Of course it's possible but it's not practical. You will end up with a rifle that has a marked over barrel, money spent on the bolt face and feed rails and bolt stop. The twist of the most .308's is 1-12 and that's enough for at least a 180 gr bullet but the big thing is the money. A typical used .308 bolt rifle may be worth $300 and a new .300 WSM costs about $610. You will have a hard time being able to sell a worked over .308 that's now a .300 WSM however. Just sell the .308 and buy a .300 WSM. Better keep the .308 and buy a new .300 WSM!

May 15, 2002, 11:02 PM	#4
TMC Member Join Date: November 7, 1998 Posts: 92	Thanks for the info. I was not aware that the base of the case was a different size. Not worth doing.