Marlin 336: 30-30 to 356?

[nhithaca]

Bought a nearly new Remington built Marlin 336 (blued, 18" barrel, big loop, plywood stocks) for not too bad a price just before everything went wild. Was thinking at the time of converting to a wildcat 375 caliber on a 307/356 case but on cobbing together a round using short 444 cases, it will not load through the loading gate. Too fat to make the turn. Did the factory 356 guns use a modified gate &/or a dimpled mag tube like the 444s and 45-70s? Has anyone converted the 30-30 336 to 356 and not had to modify the mag tube or gate? As an alternate may just rechamber to 307 if the shells will fit through the mag tube without modifications.

I don't have any issues with using a 30-30 donor gun as all the 336 based models regardless of caliber use the same forged receiver.
Looking for the range of 2,350 to 2,450 fps @ 160 grain 30 caliber, 2,250 fps @ 200 grain 35 caliber or 2,250 to 2,350 fps @ 220 grain 375 caliber all out of the 18" barrel.

[Pereira]

You can send it to JES and have it rebored 375/38-55.

RP

[Shawlerbrook]

I have Marlin 30AS’s rechambered to 307W and rebored to 356W. The 307 was done by Regan Nonneman and the 356 by JES. Although I do believe there was a small modification done to the action of the 307, neither needed the loading gate or mag tube altered. And I highly recommend both conversions.

[nhithaca]

The plan was to use JES if going to the 375 wildcat (really a 375-08 with a rim) or the 356W. I was just unsure about the size difference between the 30-30 family of cases and the larger 307/356W cases. Seems to be a real tight fit @ the loading gate.

I already have a factory 375 Marlin & a 1917 year built 1894 Winchester in 38-55 so not really looking to fill a slot in the gun case. This is just another project I have dreamed up over the last couple of years. Looking for more horsepower than a 30-30/35 Rem without the recoil of a 45-70. Like we all need more projects!!

[Shawlerbrook]

Case rim diameter is the same for the 307,356 & 30 30. Same shell holder, .506 rim diameter.

[Jedman]

Giving your idea a quick thought. A 30-30 has a rim dia. Of approx. 1/2” so to keep a cartridge diameter that size maximum should allow you to go through the loading gate and fit in the mag tube .
If you were to take 45-70 brass and turn the rim dia and extraction groove to the same dimensions as a 30-30 it would fit the bolt face, go through the loading gate and fit the mag tube.
Now take a 300 Win Mag die and cut the bottom off where the ID of the bottom of the die is .498 and form your modified 45-70 brass held in a 30-30 shell holder thru several necking dies ( homemade ) to where you can size it thru the shortened 300 Win Mag die and end up with a OAL case length of 2.00” + or - .050.
You would now have a 30 cal. cartridge that has the same length as a 30-30 and the same rim size but much more powder capacity.
This is the same idea Marlin had when they came up with the 308 MX but this would top that in capacity.

This is just a quick idea that came thru my mind but I have made 2 wildcat cartridges with this same idea that worked in a single shot rifle . Where I used a 45-70 case formed with a belted magnum die cut down to make a bottleneck case with a rim.
Whether this would cycle thru the Marlin action I don’t know ? It’s much fatter than the 30-30 but the same OAL and would fit the bolt face, Mag tube and feed thru the gate ????

I think it could be made to work and if loaded to the same pressures as top end 30-30 range would give you that more horsepower without a rebore and just need a rechamber.


Jedman

[missionary5155]

We have several 30-30's made into 38-55's and 375 Win and none had load or feed issues.

[farmbif]

I spoke to Jess about sending him a 336 30-30 to bore out 356 win, the only problem is deciding how many grooves you want other than that it seems like Childs play for him, that's what he does and it sure seems he does that kind of work cuz he enjoys it.

[missionary5155]

I would not be surprised to find out that here at our growing Cast community well over several hundred rifles have been transformed by JES Reborig.

[Pereira]

I would not be surprised to find out that here at our growing Cast community well over several hundred rifles have been transformed by JES Reborig.

I know of three personal friends that have use his services and were very happy.

RP

[Shawlerbrook]

Agreed ! JES does fine work fast and fair.

[missionary5155]

Only problem is once you get that first one and take it to the range you discover how wonderfully accurate it will shoot cast.
Plus as he keeps adding new options the door gets blown open to adventure off into calibers that used to dreams.

[nhithaca]

The problem I am trying to get my head around is that the 356/307 rounds are a lot "fatter" than 30-30 rounds (0.470" vs 0.420" at the base) and when loading through the loading gate they appear to be hanging up due to the diameter of the case, not the rim. Looking at parts diagrams for the 444 and 45-70 gun, it looks like the mag tube has a belly located just outside the receiver that allows the shell to make the turn when loading through the gate. Never took one apart to see (and I own an early 70s 45-70). If indeed the 356W works, then I most likely will try the 375-08 as I really like the 375 caliber rounds.

I am well aware of the quality of JESs work and would have no problem commissioning them to make the modifications to this Remlin when the time comes.

[bgmkithaca]

I have done what you want to do in .358 and .375 rounds but they are 1.8 inch cases instead of full length to comply with Indiana deer hunting regulations.
I found them easier to load if the groove on the loading gate is opened up a small amount and you may have to relieve the clearance where the gate hits the follower, if it is hitting the carrier the cases will be hard to push in to the magazine. Once clearance is reached they will go in like a 30-30 case will. It won't take a lot of stock removal if that is your problem. For .375 bullets Hornady does not make the flat points any more but good bullets can be gotten from Vollmer Precision or Hawk bullets, both are excellent in my experience.

[nhithaca]

Are these bottle necked cases? Would love to see more info on these.

And, yes I know Hornady shafted all us guys who use the 220 grain flat nose slugs but I expect to be using mostly cast bullets in the revised gun. Do have 3-400 of old stock flat noses on hand just in case.

[bgmkithaca]

A little late getting back on this. The cases are bottle necked and made from .356 Winchester cases, they can also be made from .444 Marlin or .307 Winchester cases. The end result is that they look like a shortened .356 round. I don't hunt anymore and gave the rifles to my son to use. He got the loading data so can't provide that for you. I do remember that the .375 version was a real bulldozer on deer and kicked pretty hard in a 336 Marlin.

[lar45]

MbtCustom built a 30/45-70 on a Win 1886. Pretty sweet rifle with draw filed Octagon barrel. I don't remember the exact numbers he got from it. Pretty cool project though.
The 375-356 sounds very interesting. The 358 win can really perform.
The only downside I see is custom loading dies.

[Shawlerbrook]

Farmbif, I had the same question about the number of grooves when I had my 356 done. Asked JES and he seemed to indicate not much difference. I went with 5 just because and am extremely happy.

[rockrat]

I would think 375-08 dies would work fine. I use 358 win dies for my 356Win (JES did the conversion) and have been happy with it.