Potential stupid ?

[JagerDog]

Can a pre '64 Mod 70 in .264 Win Mag with an eroded throat be opened to .338 Win mag or is that a fool's errand?

The math appears to work, but I've no idea of the process.

Advantage/disadvantage vs. rebarreling to .338?


Ballpark cost (either path) ?

[justMike]

I don't see how the the math works out when you have two different bore diameters, unless you're talking a new barrel.

[ar15barrels]

Can a pre '64 Mod 70 in .264 Win Mag with an eroded throat be opened to .338 Win mag or is that a fool's errand?

The math appears to work, but I've no idea of the process.

Advantage/disadvantage vs. rebarreling to .338?

Ballpark cost (either path) ?

What you are asking about is called reboring.
Then after boring, the barrel gets rifled and then rechambered.
This is usually only done on guns where you want to retain the original barrel exterior and markings, but you want to go to a larger bore to eliminate the worn out smaller bore.

http://www.35caliber.com/8.html

http://www.cutrifle.com/reboring.html

6.5 up to 338 is 5 steps up.
You would be better to go to a 7mm mag or a 300 mag.

[JagerDog]

I don't see how the the math works out when you have two different bore diameters, unless you're talking a new barrel.

By math, I mean there's material (much is identical except bore diameter)

[JagerDog]

What you are asking about is called reboring.
Then after boring, the barrel gets rifled and then rechambered.
This is usually only done on guns where you want to retain the original barrel exterior and markings, but you want to go to a larger bore to eliminate the worn out smaller bore.

http://www.35caliber.com/8.html

http://www.cutrifle.com/reboring.html

Yes.

There's a certain sympathy to the original rifle, but not a deal breaker.

End results (accuracy) compromised? (seems not compared to original)

Metallurgy of early 60's inferior?

Idea of costs on either method? (I see $250 listed...that's seems too reasonable...must be more to it???)

[JagerDog]

6.5 up to 338 is 5 steps up.
You would be better to go to a 7mm mag or a 300 mag.

I have another pre-64 (featherweight) in .264. I have a "classic" in .300. 7mm doesn't buy me anything really. The "concept" was to basically turn the "Westerner" into an "Alaskan", keeping with the family of Win Mags which came out of together (.264, .338, .458 "African" ). I seriously doubt I'll be using a .458 unless I win the Lotto.

[Spyder]

I seriously doubt I'll be using a .458 unless I win the Lotto.

I've used my 458 WinMag for cottontail.

[edgerly779]

Not much meat left on the barrel. Rebarrel or go with Randalls suggestion.

[JagerDog]

Not much meat left on the barrel. Rebarrel or go with Randalls suggestion.

Was a factory Mod 70 .338 a larger O.D. than a .264?

Stock is already glass bedded for this barrel.

Would be seeking "hunting accuracy".

[JagerDog]

I've used my 458 WinMag for cottontail.

I've killed jacks with .264. That was impressive. Are there even "varmint" bullets in .458?

[Sailormilan2]

I've used my 458 WinMag for cottontail.

Well, you certainly don't have to worry about them charging when wounded.

[LynnJr]

JagerDog
Give Cliff Lebounty a call.
He has done a few for a friend of mine and they shoot just fine.
If you don't need a new chamber it isn't that expensive.
If you start off with a 22BR going to 6BR or 25BR,7BR or 30BR is a breeze.

[Whiterabbit]

I've killed jacks with .264. That was impressive. Are there even "varmint" bullets in .458?

All of them.

[Fjold]

Reboring is a pain. It's easier to just spin on a new barrel. Saying that, reboring is just drilling the existing hole larger and then re-rifling the bore. For a .338, as long as the barrel wall thickness at the muzzle is about .125" or so (diameter of .588") it will work.

I bought a 458 Win Mag that had a .660" diameter barrel at the muzzle, which is .102" wall thickness and it was way too light up front. It jumped straight up when I shot it and tried to give me a black eye. I re-barreled it with a .750" muzzle diameter barrel and it's a lot nicer now.

You can shoot varmints with the 458 Win Mag, use the 250 grain Barnes TSX designed for the SoCom and 45.70, crank them up at 3,000 fps or so and they will demolish ground squirrels, jack rabbits, small cars, etc.