As the title reads, I have a pretty nice pre 64 Win 70 in 375 Wby that I bought pretty much for parts or a project. I have not yet received it and am not sure just what I am going to do with it.

I may leave as is and keep or sell it.

I may ream to 375 Rem Ultra Mag and keep or sell it.

I may rebarrel to 458 Lott or 416 Rem Mag

I may sell the barrel; I may sell the barreled action.

I am NOT offering this for sale here at this time. I am just gauging people's wants, advice, etc.

If I did sell it, for the right price of course, does anyone have interest in a nice looking non original pre 64 Win 70 in 375 Weatherby? The details are below:

Nice original stock with 13-1/2" LOP, nice checkering, Decelerator pad, ebony forend tip, one steel recoil cross bolt, nicely reblued action including bottom metal.

Classified section

Since it's an "extra" which presumably means you already have one, a 416 barrel would be super easy and allow you to switch it back. If you don't already have one, they are nice rifles so keep it as is.

Years ago I bought a pre-64 Model 70 which someone had "improved" by running a .375 Weatherby reamer in its .375 H&H chamber. Problem was, he generated .021" excessive headspace in so doing.

He had also installed an Echo side mount, which was incapable of holding the Lyman Alaskan scope mounted with it against the recoil of the .375. He had filed notches in the scope tube and installed set screws in the mount rings.

This was in the late 60's and Winchester was still very amenable to fulfilling customers' wants, so I sent the rifle back to Winchester, requesting a new barrel and receiver and requested the old receiver back. In due course I received the rebuilt .375 H&H and the receiver.

I had the receiver barreled in .450 Watts Magnum and had a Griffin & Howe side mount installed in place of the Echo, using the original Echo holes. Lyman was good enough to completely refurbish the scope, so I had it reinstalled as well. Other than the bolt, most of the other parts to complete the action came from my junk box. The bolt was scavaged from a .30-'06 Model 70, which was then sent to Winchester to have a replacement bolt fitted.

The rifle accompanied me on my last trip to Africa, where it performed flawlessly. It still occupies a place of honor in my gun room.

My recommendation would be to rebarrel in .458 Lott.

You cannot simply rechamber a .375 Wby to .375 RUM without setting the barrel back.
It won't clean it up.
.375 RUM will not even clean up a .375 H&H shoulder-neck1 juncture, and the .375 WBY is further from the bolt face than that, so it would be a really ugly compound shoulder-neck juncture unless you cut the breech off and re-thread before rechambering.
Plus, if that .375 Wby has the original throat from pre-2002, you have .750" length of parallel-sided free-bore that will remain.
Even I don't like that, and much prefer the 0.370" length of current CIP .375 Wby spec. for free-bore.
Unless it is the original "Big Nan" of Hal Waugh, or was chambered with the current CIP spec reamer, then re-barrel it.

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RIP you sound like you know something about this. I looked at the cartridge dimensions in my load manuals and it surely looked do-able to me. I will take a closer look.

I may go with 300 Weatherby, 416 Rem, 458 Lott, or leave as is.

If left as is I may keep or sell, who knows; I have a nice pre 64 in 375 H&H and loads of brass.

I am open to more suggestions. Thanks to all.

I have a new version Pre '64 M70 in 375 Wby and just love it. I think I might just leave the rifle as is if it shot well. 2900 FPS with a 270 TSX is easy to achieve and makes the 375 Wby even more of an all around cartridge.

Mark

I have a new crf M70. It was originally a 458 WM, and the original owner had it rechambered to 458 Lott.

Think 500gr bullets at 2300+/-fps.

Want a bigger hammer? Go 470 Capstick.

JES Reboring might be able to bore the barrel for you and keep the re-work to a minimum.

quote:

Originally posted by MARK H. YOUNG:
I have a new version Pre '64 M70 in 375 Wby and just love it. I think I might just leave the rifle as is if it shot well. 2900 FPS with a 270 TSX is easy to achieve and makes the 375 Wby even more of an all around cartridge.

Mark

Yep, if it is accurate and gets 300-grain Nosler Partition Weatherby factory ammo up to 2700 fps or more from a 24" or longer barrel, leave it as it is please.
There is no better all-purpose rifle than a .375 Weatherby, especially a CRF M70.











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Wow RIP, thanks for the trouble there! I have a friend who works out of Loon Lake, MI and has for years. I can't remember which big name gunsmith or reamer maker he knew out there, but I want to say it was Dave Manson before he left Clymer??? My memory has been jogged but that info was from a long time ago! Long before I had internet. My friend is a pretty good gunsmith (side hobby) but he sure knew all of the big boys.

I looked only at shoulder and body dimensions. I never thought the neck would be an issue or gave that extra .010" or thereabouts for the belt hanging out of the chamber. Anyways it looks like the 375 Rem Ultra Mag is on the verge of dying out anyhow. I think the 375 Ruger is helping it's exit, that and too hard a kicker for the bore size. Decisions, decisions!

airgun1,
Yes, that is a Dave Manson reamer. He called his business "Loon Lake" before it became Manson Precision Reamers.
I guess he was a rifle looney before John Barness "coined" the term.

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quote:

Originally posted by airgun1:
Wow RIP, thanks for the trouble there! I have a friend who works out of Loon Lake, MI and has for years. I can't remember which big name gunsmith or reamer maker he knew out there, but I want to say it was Dave Manson before he left Clymer??? My memory has been jogged but that info was from a long time ago! Long before I had internet. My friend is a pretty good gunsmith (side hobby) but he sure knew all of the big boys.

I looked only at shoulder and body dimensions. I never thought the neck would be an issue or gave that extra .010" or thereabouts for the belt hanging out of the chamber. Anyways it looks like the 375 Rem Ultra Mag is on the verge of dying out anyhow. I think the 375 Ruger is helping it's exit, that and too hard a kicker for the bore size. Decisions, decisions!

You will find no more generous person on any internet forum than RIP! Would that the world had lots more folks like him.

Not to dis any of the other fine folks round here but, RIP is top shelf.

quote:

Originally posted by airgun1:
RIP you sound like you know something about this.

I just read this!

RIP has a PhD in large bore rifles! I call him Dr. RIP because if his wealth of knowledge!

Ah shucks Karl, you are going to spoil my carefully cultivated image here as a peculiar curmudgeon/ Ugly American.
Thanks anyway.

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quote:

Originally posted by RIP:
Ah shucks Karl, you are going to spoil my carefully cultivated image here as a peculiar curmudgeon/ Ugly American.
Thanks anyway.

Riflecrank Internationale Permanente
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Well, that might apply to some folks, maybe even me , but never to you, sir!

Well it is indeed extra. It is listed in the classifieds.

A 375 Weatherby isn't worth the trouble for me for the small gain over a 375 H&H. 375 Rem Ulta is not doable without setting back the barrel, and a 375 Ruger would be best attempted on a standard length action; plus the cannelures not being able to used on many bullets when reloading the Ruger.