Rebarrelling a 375BB to 444

[andym79]

Hi guys, I have a 375W big bore which I want to get rebarrelled to a 444 marlin.

There is nothing wrong with the 375W, I just have a 38-55 and as I only shoot cast to me the 375W is pretty much just a duplicate of the 38-55 offering no more without going to jacketed.


The 444 however is more than the 38-55 at cast velocity.


Obviously I need a new barrel I was thinking with a 1:20".

I also am pretty sure I will need new cartridge guides and the body is a fair bit wider, do I also need a new lifter?

As to the bolt the rim difference is .506" vs .514", so would it need modifying? Will a new magazine tube be required?

[saleen322]

Just a suggestion but you may want to sell the 375 Win and use the money to buy a 444. A 375 Win in decent condition is worth money in the US. I cannot speak to prices in Australia but I would at least check into it if you have not already. YMMV

[MT Gianni]

Second on the sell and replace it.

[pietro]

Hi guys, I have a 375W big bore which I want to get rebarrelled to a 444 marlin.

Obviously I need a new barrel I was thinking with a 1:20".

I also am pretty sure I will need new cartridge guides and the body is a fair bit wider, do I also need a new lifter?

As to the bolt the rim difference is .506" vs .514", so would it need modifying?

Will a new magazine tube be required?




The parts (guides, magazine tube, etc) from a angle-eject .444 Model 94BB Timber Carbine or .444 94BB Shadow
would fit your rifle's receiver/etc.

The barrel can be simple re-bored/re-rifled to .429" & re-chambered, but a .444 BB94AE barrel will screw in, but need to have some machining done to it for the .375's tol-mounted extractor, and maybe to fit the magazine hangers/bands and/or forend.

If your .375 BB94 happens to be one of the rare .375's built on the angle-eject BB94, them it's all a simple parts swap.


.

[OlDeuce]

I just did a 1894 carbine in .44x2.080 and is working very well! been doing a lot of test shooting I call this a .44-56WC
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Ol Deuce

[andym79]

What bits did you need to modify? I have been entertaining the idea of either a slightly shortened 444 a 444 x 2.039" or a 444 necked to 40 cal, essentially a slightly smaller 40-65.

[OlDeuce]

What bits did you need to modify? I have been entertaining the idea of either a slightly shortened 444 a 444 x 2.039" or a 444 necked to 40 cal, essentially a slightly smaller 40-65.

Andy........ I did a 20'' 70s .44mag barrel.....picked up a .444 ream short cut the chamber to 2.10 . trimmed the 444 brass back to 2.080 ..

[Texas by God]

Andy........ I did a 20'' 70s .44mag barrel.....picked up a .444 ream short cut the chamber to 2.10 . trimmed the 444 brass back to 2.080 ..

That is cool - the "44-50 WCF" lol. Best,Thomas.

[OlDeuce]

That is cool - the "44-50 WCF" lol. Best,Thomas.

It does hit hard !!!! :-) :-) Ol Deuce

[OlDeuce]

Cutting the face !186127

[andym79]

The parts (guides, magazine tube, etc) from a angle-eject .444 Model 94BB Timber Carbine or .444 94BB Shadow
would fit your rifle's receiver/etc.

The barrel can be simple re-bored/re-rifled to .429" & re-chambered, but a .444 BB94AE barrel will screw in, but need to have some machining done to it for the .375's tol-mounted extractor, and maybe to fit the magazine hangers/bands and/or forend.

If your .375 BB94 happens to be one of the rare .375's built on the angle-eject BB94, them it's all a simple parts swap.


.

Unfortunately its a top eject! Does the 444 marlin need a different magazine tube the rim diameter is only .008" larger than any other cartridge?

So at a minimum a new extractor groove, but possibly new dovetailing and chambering a bit deeper too?

[OlDeuce]

Unfortunately its a top eject! Does the 444 marlin need a different magazine tube the rim diameter is only .008" larger than any other cartridge?

So at a minimum a new extractor groove, but possibly new dovetailing and chambering a bit deeper too?

No the mag tube and all that stuff is perfect ....what I have found in the 1894 bolts it ends up as a perfect fit to the .444 face of the brass!! :-)
the trim that I do is only to help the extractor go over the face edge and makes the bolt close easier thats it :-) Ol Deuce

[OlDeuce]

The part of all this in the early 1894 actions is opening up the rails ! the mounting screws will almost go away! on the the later post 94s the rails and
mounting screws are in a different location plus you can buy the rails new from winchester for the .444 94 actions...Ol Deuce
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[OlDeuce]

My first few brass was formed from 30-40 and fire formed , not all were a success :-( then I bought .444 and was much easier to work with
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[andym79]

I really think a slightly shorter cartridge is the way to go, more chance of feeding through the action and for most 44 caliber bullets the tiny reduction in case size will hardly be noticeable.

What size bullets and loads do you find to work best in it?

[OlDeuce]

http://castboolits.gunloads.com/attachment.php?attachmentid=185569&d=1484791880&thumb=1 this was with 28.9 gr of IMR3031 and a 310gr GC Lee mold at a 100yds........this was the Best of the tests so far
the 220gr RN with 30gr. IMR3031 was low and all over board this all was fired from a 20'' .430 1:38 twist mag barrel MFG. mid 1970s Ol Deuce
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