Whats required to convert a Marlin 1895 to 50 Alaskan?

[Arrow]

I build custom boltguns so I'm very comfortable on the mill and lathe. Ive never really worked on lever guns and have been kicking around the idea of turning my JM stamped 1895G into a 50 Alaskan for a fun project. My questions are:

Where do you source a .510 caliber blank for this project?

What all needs to be done to the receiver to allow loading, feeding, extraction, and ejection? I'm sure the ejection port and the loading gate opening need to be opened up. Do the mag tube and loading gate need to be replaced? What about the bolt face being the rim is wider on the 50 Alaskan (I assume at least).


Any safety hazards I need to be concerned with by cutting metal on the receiver and putting a bigger bored barrel on it? I have read some guys don't like using 1895/336 receivers and prefer the 86 or 71's but the 1895 is what I have and I know there are guys out there running them just fine.

[Jedman]

The problem I see is the barrel shank diameter would be very thin, M 336 and M 1895's use the same size.

Jedman

[pietro]

.

IIRC, .50 Alaskan conversions were (quite properly) the domain of the Winchester 71's, 86's & 1886's, which are MUCH stronger actions than the Marlin 336/.444/1895.

Additionally, because of the thinner barrel required by the thinner Marlin receiver size, they can blow out the bottom of the barrel in the larger (.45cal) bores with strong loads.

Since the .50 Alaskan is much more powerful than modern .45-70 loads, I would never consider a Marlin for conversion to .50 Alaskan.

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[lar45]

A long time ago I read that the Marlin required a special high strength steel for the barrel because it ends up being so thin at the shank.
Maybe use 4340 instead of 4140?

[pietro]

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IIRC, that was for either the .356 ER (extra range) or the .338 Marlin - both of which have more meat in their barrels due to bores smaller than the .45's

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[Stockcarver]

Been there. Enlarged threads in the receiver. Enlarged barrel shank to match. Pac Nor barrel. Over 20 years ago.

This one is the 510 Kodiak, longer case than the 50 Alaskan. I have reamers for both the 50 Alaskan and the 510 Kodiak.

Would I build another? Not likely. Expensive in both man hours, materials and special tooling.

5500 foot pounds!! Proofed with a special M98 test rifle and the Oehler M43 strain gauge system.



The sled weighs over 100 pounds. 30 foot lanyard, I hid behind the pickup on every shot. Shooting into a big berm covered by the brush.







45-70 on left



I made all the dies.





19 inch barrel. Two mercury recoil absorbers in stock. Thick Sorbothane pad. Brake of my design. Put in a stock through bolt and enlarged tang screws. Bedded in Acraglass. Bottom rifle is a stock 1895 in 45-70. Changed the tube magazine, the bottom of the barrel has a groove machined for clearance. Lots of work enlarging the loading port and the ejection port. Robar Black Roguard and the silver is NP3. Interior parts are NP3 coated (NP3 is slick).



Dialing in in the vertical mill prior to enlarging the receiver threads.



Making room for the barrel at the shroud.

[Stockcarver]

Profiling the barrel



Testing the receiver threads for size



Cartridge and rifle designed by Mic McPherson.

The bronze solid on the far right weighs 470 grains, not 375 as shown on the card.

[Stockcarver]

Setting up in the mill to machine a groove for the magazine tube



Barrel Vise



Enlarging receiver threads



Dialing in the barrel for threading and chambering. Barrel was too short to go through the headstock so I went this way. Turned a short area at the muzzle true to the bore centerline prior to this step.

[Arrow]

Thanks for all the info. What thread size did you open the receiver up to? Also what are you doing with the receiver in the lathe with the mandrel running through it, you said something about opening up the shroud? Did you have to open up the loading gate or ejection port at all for the fatter casing? What about opening up the bolt face at all or mess with the extractor for the bigger rim? Thanks

[Jedman]

When looking at the 50 Kodiak next to a 45-70 I don’t see where you could get 5500 ft. lbs. of energy from a cartridge that size as your into the range of the 458 Lott. And with the limit of OAL in a Marlin action the bullet is going to use a lot of the powder capacity so is it really worth all of the modifications to make this work ?
The rifle is unique and different but I just don’t see the Marlin as the right platform to use a super sized cartridge in.

Jedman

[Stockcarver]

When looking at the 50 Kodiak next to a 45-70 I don’t see where you could get 5500 ft. lbs. of energy from a cartridge that size as your into the range of the 458 Lott. And with the limit of OAL in a Marlin action the bullet is going to use a lot of the powder capacity so is it really worth all of the modifications to make this work ?
The rifle is unique and different but I just don’t see the Marlin as the right platform to use a super sized cartridge in.

Jedman

The larger diameter of the .510 case holds more powder. Careful test firing with the Oehler system allows selection of a powder with the correct burning rate to obtain the desired velocity/energy without exceeding the design pressure of 45,000 psi.

Takes a lot of work, both in the rifle construction, and the firing of test loads to obtain what we were looking for.

That is a 458 Win case upended in the .510 case. Considerable capacity difference.



If I build another, I will use the Browning 71 action. After all the 1886 Winchesters handled the 50-110 cartridge just fine. In fact, I would build a 50-110 on the 71 action, rechamber my proof barrel for the 50-110 cartridge and run trials on the Oehler 43 system.

Yea, you can build a 510 on the Marlin, but my experience says is just is not worth the time expended and the tooling required. Plus you have to form cases. I formed from 348 Win brass.

I actually had a 71 in the shop to convert to a big 50, using the 500 Nitro Express Case. Health issues forced me to cancel the project. Finally found out what was going (diabetes) and the meds put me back on even keel. Cataracts were creeping up, not good to have failing vision in a machine shop! Lens implants cured that.

A gent would be real foolish to build a rifle of this nature without pressure testing equipment. Sure, you can obtain the velocities desired with a variety of powders, but not knowing the chamber pressure puts you into dangerous territory.

Photo below is about half of the shop. You need all of this, and more, to build a rifle of this nature.

[Stockcarver]

Thanks for all the info. What thread size did you open the receiver up to? Also what are you doing with the receiver in the lathe with the mandrel running through it, you said something about opening up the shroud? Did you have to open up the loading gate or ejection port at all for the fatter casing? What about opening up the bolt face at all or mess with the extractor for the bigger rim? Thanks

I will have to look through my notes, after all this was in 1998 and 1999. Lot of work opening the loading gate and ejection port. The receiver on the arbor in the small South Bend lathe: truing the front of the receiver and opening up the area to allow the larger diameter barrel to fit.

[Nobade]

And here I am, way more interested in the shop than the rifle. Nice setup!

[Jedman]

Yes for sure you have a awesome shop ! Jedman

[Arrow]

Did you get a chance to review your notes to see what thread size the receiver was opened to as well as dimensions of the loading gate and ejection port? Thanks

I will have to look through my notes, after all this was in 1998 and 1999. Lot of work opening the loading gate and ejection port. The receiver on the arbor in the small South Bend lathe: truing the front of the receiver and opening up the area to allow the larger diameter barrel to fit.

[john.k]

Take the barrel out of your 95,and all your questions will be answered.....even the 45-70 parts are scary thin to anyone used to bolt rifles......Id think the tenon thread could only be enlarged eccentrically towards the top,and even then ,not by much ....I often thought Marlin could have left the top part of the reciever cylindrical,like a Winchester 94,instead of reducing the part over the tenon.

[samari46]

Guess you won't be moving any of those Kennedy tool boxes around anytime soon. Always felt that Marlin could make a stronger rifle by not cutting down the top of the receiver ring on their rifles and deepening the height of the receiver there by leaving a stronger receiver ring, more metal between the threads of the receiver and more metal for the mag tube. In any event a beautiful rifle. How much does she weigh fully loaded?. Frank

[M-Tecs]

Nice shop. If I ever get mine organized enough I will post picture also.

[Arrow]

back to top? Any info on threads used or dimensions on ejection port and loading gate?

[Arrow]

@stockcarver