444Marlin/375Win. Improved

[calaverasslim]

HUH!! [smilie=1:

A friend of mine, darn fine machinest and even better gunsmith has decided to take one of his BB94 .375's and ream it out to take a 444Marlin case that has been necked down to .375 Winchester. trying to maintain the same or almost the same case length. Adjusting for the shoulder, or course.

I just wanted to throw this out in case some one has heard of this or even tried it in the past.

Your thoughts, please! :coffee:

[felix]

CS, it's all about case capacity. More capacity, more possible power. Anything over about 2400 fps is a mite much for various batches of reformulated lead. With large diameter boolits, the speed limit should be lower unless lead is formulated for the purpose. Match the case size to the maximum boolit weight and speed!!! ... felix

[Scrounger]

Slim, you just described the .375 JDJ. J D Jones done that years ago. There are factory Contender barrels available for it. It is a heck of a cartridge, powerful enough for an elk. Recoil has to be downright unpleasant. There is loading data for it in several manuals. He can save himself a lot of developmental cost and work just by using the JDJ version.

[Frank46]

I think one of the writers for either handloader or rifle magazine did something quite similar some years ago. Just looked in one of my books. Ken Waters did one called the .375 express based on the 444 marlin case. Frank

[Marlin Junky]

The .375 JDJ is a neckless wonder. Encourage your friend to do better with respect to a CB cartridge:

http://www.stevespages.com/jpg/cd375jdj.jpg

A .356 Win. necked up to .375 with the shoulder pushed back creating a 30-30 length neck would be an improvement for CB use. You might be able to increase the powder capacity by 5 to 10 grains over the .375 Win.

[JohnH]

I have a 375 JDJ, had a 38-55 (lower operating pressure 375 Win) A 38-55/375 Win barrel is at the top of my want list. Perhaps Santa will be nice to me this year. The 375 JDJ is barely cast capable. Too much powder capacity. 4064 will break your shoulder, 4350 will barely burn. Run as it was meant to be, it will kill your shoulder and anything you point at.

It was a 303 Brit case that Ken Waters turned into a 375

[Doughty]

I've got a project in progress along these lines. Basicly a .30-40 Krag blown out to .375. I like the Krag neck length.

[Nrut]

I've got a project in progress along these lines. Basicly a .30-40 Krag blown out to .375. I like the Krag neck length.
Bingo Old Vic....I would love to get one of my Browning Low Walls rebarreled & chambered for such a creature....In Handloader #129 Paul Matthews rebarreled and chambered a Ruger #3 to what he called 37 Rimmed which is a .30-40Krag necked up to .375.......but this is not new as the 38-50 RemHepburn is very close to the above....from what I have read...
Link to 37 Rimmed
http://www.loaddata.com/members/search_printable.cfm?metallicid=1248&MW=&PM=&PT=

JohnH...
K.Waters may have done a .375 on a .303 case but his ".375 Express" was based on a .444 Marlin case around 1968("BIG BORE RIFLE AND CARTRIDGES")....I don't know when J.D. Jones came out with his .375JDJ but I bet is was after 1968......Makes ya wonder....I'm like you a big .375 fan....Are you wanting to get a custom .375-55 barrel for your Encore?.......:)

[Frank46]

JohnH, nope no cigar. Custom cartridges page #288 bottom of the page. "Resize 444 marlin brass full length in 375 express sizer die". There was an article where he had a mauser rifle in some german cartridge (may be wrong here darned CRS again) and I believe he had it rebored to 375 caliber and made up this cartridge to fit and fire in it. Could have been a british cartridge also. Hope this helps. Frank

[JFE]

Paco Kelly experimented with something similar to the 375/444. He basically used an improved 356W necked up to 375, which ends up somewhat shorter than what you described. He reports a big performance increase over the stock 375 Win but his loads do seem to push the limits somewhat.

Assuming that you want cycle loaded ammo through a 94BB, I think you might find a straight 375 on the full length 444 case too long for any jacketed and quite possibly most cast designs.

Joe

[rockrat]

The 30-40 blown out to .375 comes awfully close to the 38-72. Would be a bit shorter than the 38-72. Thinking of chambering a NEF 38-55 to 38-72 or reboring a 95 winniy to .375 and chambering it for the same. should be a great cast gun.:-D