Custom Mosin build. Need help with caliber. Don’t hate.

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Thisisyourcaptin

Thisisyourcaptin

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So. I did some trading today with a local here in Ohio and scored a made by Remington Mosin Model 91 (not 91/30) flat top Mosin receiver and bolt. As well as a 1911 and revolver. But that’s it. No barrel, stock, trigger or anything else.

I am not in a hurry with this and have till next hunting season to finish it. I’m looking to get a barrel made for it from McGowen and need to decide on caliber. I don’t have, own, or reload 7.62x54r and don’t care too. I reload 45-70, 35 Whelen, 357 mag, and 45 acp.

I have seen a few people rebuild Mosin to 45-70. I don’t care two. I have a high wall and an 1886 that is enough for me. I have my Mausers in 35 Whelen and want to make the Mosin one too.

So, is the Mosin action strong enough for 35 Whelen? It is going to be a hog gun that I don’t mind getting dirty. Kinda save my nice mausers for my nicer hunts.

Don’t hate. I know is a Mosin. Yes this is going to cost more than it will ever be worth. But I don’t plan on selling it either. I love building and seldom ever sold anything I build. If these calibers don’t work then I can do 30-06. I have wanted to for a while. But don’t own anything in it yet. So have waited.
 
6.5 Swede or 6.5-06 would be pretty cool in my opinion.

Seems like you want a bigger bullet though.

There's 338-06 and 40-06 if you're so inclined.
 
One of the issues is that you will have to address is that the Mosin is designed around a rimmed cartridge magazine and can be a bit fussy on operating on those via the cartridge interruptor which is designed to help prevent rimlock. There is a reason that typically folks convent rimmed cartridge rifles to other rimmed cartridge rifles and no-rimmed to other no-rim cartridges and that reason is feeding from the magazine. A Whelen cartridge has a bit higher psi rating than the Mosin was designed for. Then you have other fun issues such as the bolt head adaption, etc.

If the receiver is untapped, I would probably follow Varminterror's advice as a collector might pay quite a bit for an unmonkeyed with bare 1891 receiver, particularly if it was a French made one.
 
boom boom said:
One of the issues is that you will have to address is that the Mosin is designed around a rimmed cartridge magazine and can be a bit fussy on operating on those via the cartridge interruptor which is designed to help prevent rimlock. There is a reason that typically folks convent rimmed cartridge rifles to other rimmed cartridge rifles and no-rimmed to other no-rim cartridges and that reason is feeding from the magazine. A Whelen cartridge has a bit higher psi rating than the Mosin was designed for. Then you have other fun issues such as the bolt head adaption, etc.

If the receiver is untapped, I would probably follow Varminterror's advice as a collector might pay quite a bit for an unmonkeyed with bare 1891 receiver, particularly if it was a French made one.
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After doing some research. It seems that your are right. It’s going to be quite the undertaking. Frankly the hardest of which is finding someone to either weld and machine the bolt or even just machine it. The barrel is the easiest part of all this it seems. I have found a few threads on other forums and they all seem to point to making it a 45-70 as the easiest of them all. BUT you still have to work the bolt face. Not many gunsmiths find that a worth wile prop. I guess I was hopping it would be easier. As in a few more gunsmiths out there willing to under take it. I can build this as a 7.62 sportier for a much cheaper proposition. maybe that’s the route I should take.

The 7.62x54R is no slouch of a round. With the right barrel and reload data it is something to work with. I need to do something on this. I really dont want to invest in more reloading stuff. While cheaper it just means more to learn. as a pilot I’m only home two maybe three days a week and I’d rather spend my time with stuff I know or shooting. 45-70 isn’t out of the question just not what I really want.
 
I think .348 Winchester would be a good bet. This round can also be easily necked up to .35-348 and have similar ballistics with a much better bullet selection. The rims are very close. The original X54R round has also been successfully necked up to 9.3mm and used in eastern Europe and Russia for large game, .35 should be just as doable. Also don't be so quick to dismiss the X54r round. Quality brass is readily available from PRVI and Lapua, and the 174gr Hornady rn would be a fantastic choice for your stated purpose.

The mosin is a strong action with shorter rounds. Successful military conversions have been made in 8x57, but converting into a longer round such as 30-06 has been problematic. Bannerman tried it and they were a bit "explody". Something to do with the length of the receiver ring. I have heard they are also difficult to rebarrel, so you may have issues with .35 Whelen in addition to getting the bolt face to fit the rimless round.
 
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If you realistically compare the cost to rebuild the action and buy a barrel vs buying a set of dies it is a simple decision. I know that I love shooting my 91/30's so I do not understand your reluctance for using a round that is readily available and quite capable of dealing with wild hogs. But then, I don't understand a lot of things.......
 
I agree that the 7.54x54r is still used quite successfully as a hunting round in Europe and its ballistics resemble that of a 1903 in its abilities to handle different bullet weights. Depending on the circumstances, it might be possible to neck up a 7.54x54r to .35 caliber if you are so inclined to shoot a wildcat. It might have already been done AFAIK. Someone like THR poster LoonWulf might know among others including Varminterror above or Win243xb Here is an old gunboards forum post on the subject and there are other such things floating around. The Finns apparently did a 9.3x53r and here is one such project https://www.sporterizing.com/index.php?/topic/9003-95x54r-pig-gun-project/

You can find out a bit on your receiver's history via the pictures of different markings found on either http://www.mosinnagant.net/ and here http://7.62x54r.net/MosinID/MosinM.htm Some of the makes are more rare than others and if the receiver has not been changed, a milsurp collector might take it off your hands for a fair amount of money. Entropy, a THR poster, knows his Mosins as well as other milsurps so might be able to guide you.

If you want to accurize it, Joshua Smith, a THR poster has quite a few tips including videos at his internet shop for Mosin accurizing accessories http://smith-sights.com/

I would also study carefully what the Finns did with the Mosin to accurize it and make magazine feeding more reliable from them. There is also a relatively recent series in the old Shotgun News on Reid Coffield's sporterizing a Mosin to good effect. There are also "sniper" bent bolt bodies floating around already so that part would be done--try places like Sarco, Ebay, etc.

Some time back, Sarco or one of the other milsurp sights, maybe Classic Firearms, sold bull barrels chambered for the Mosin that apparently were well received in accuracy by those that had them--if my memory serves, these were old Russian machine gun barrel blanks that were threaded, rifled and chambered to fit Mosins with only finish reaming required.

The Mosin shares some design similarities to the Mauser 71/84 in the bolt design, the Mannlicher in the magazine design (without the whole clip feed system), and some unique features itself. If you look more broadly at sportering some of these, you might get some ideas of how to tackle things like magazine redesign and feeding, bolt alteration including the bolt head, ejectors, extraction, etc. on conversions to a rimless cartridge. It has been done before but it does require substantial alterations.

Good luck with whatever you decide to do.
 
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Sorry OP, missed your second post. Regarding reloading the X54R cartridge. It is really no more complicated than any cartridge currently in your arsenal. Powders suitable for the .35 Whelen are also suitable for X54R. I prefer IMR 4064 for lighter bullets, IMR 4350 for heavies. Really all you need are dies, brass and bullets, load data is widely available.

I have taken several deer with the round and 174gr Hornady RN. I've found performance very similar to the old Rem Core Lokt 180 RN 30-06 loading. I've also successfully competed with the round to 600 yards in CMP Vintage sniper competitions. When you move the headspace to the shoulder by backing off your sizing die, it has as much accuracy potential as the .308 with better heavy bullet performance, approaching the 30-06.
 
LRDGCO said:
30-40 Krag. In the Mosin, you can load it to .308 Win performance.
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A bit easier to find ammo for with about the same outcome is the .303 British, brass and bullets are very common but I have no idea about how well it or a Krag would feed from the magazine or what bolt head alterations would be needed. The Canadian solution, like your Krag idea, is the .303 Epps which is a .303 wildcat upgraded to about .308 stds. I have Krags and Enfields and the Krag is a fine round but brass has been a bit hard to come by until just recently. The U.S. won international Palma Match, in I believe about 1907 with an upgraded Krag cartridge and spitzer bullet combo which included shooting at range. http://sabisley.com/history-of-the-palma-match/
 
Both the 30-40 and 303 British have a smaller rim diameter than 7.62x54R (.545" and .540" for each respectively vs .567" for the Russian). A .308 Epps, would work well (no sense not to use the more standard groove depth in the US) but the 30-40 needs nothing more than a stronger receiver to deliver .308 Winchester performance. While I have been able to find 30-40 brass without too much trouble, 303 brass is more available, which argues in its favor.
 
It's pretty common in Finland and Russia to neck the 7.62x54 up to 9mm, which would just about match the 35 Whelen and still fit and function through the action. If not that I'd go for something totally off the wall like .405 Winchester or maybe 6.5 Remington mag. There action is plenty strong, I have seen one chambered in .338 Lapua. It had to be fed single shot by removing the bolt for every shot.
 
LRDGCO said:
Both the 30-40 and 303 British have a smaller rim diameter than 7.62x54R (.545" and .540" for each respectively vs .567" for the Russian). A .308 Epps, would work well (no sense not to use the more standard groove depth in the US) but the 30-40 needs nothing more than a stronger receiver to deliver .308 Winchester performance. While I have been able to find 30-40 brass without too much trouble, 303 brass is more available, which argues in its favor.
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I agree on the receiver plus a different magazine design as the Krag's internal mag can create problems with feeding spitzer bullets. I would like to acquire a Ruger No. 1 or No. 3 rifle sometime for that reason. Using a .308 would give a bit more flexibility on bullets but the .311's have become more common over time thanks to the internet. A new custom barrel though would more or less point toward using the .308 bore. FWIW, rim diameters and even thickness vary quite a bit on the .303 British among manufacturers. Here is one such experiment on TFL forums measuring them--https://thefiringline.com/forums/showthread.php?t=535292 From some reports, do not know whether it is true, some recent manufacture Krag brass case head diameters are coming out the same as .303. If Prvi is making the private label .30-40 Krag brass, this might explain that.
 
rule303 said:
It's pretty common in Finland and Russia to neck the 7.62x54 up to 9mm, which would just about match the 35 Whelen and still fit and function through the action. If not that I'd go for something totally off the wall like .405 Winchester or maybe 6.5 Remington mag. There action is plenty strong, I have seen one chambered in .338 Lapua. It had to be fed single shot by removing the bolt for every shot.
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Now this has me thinking. I just don’t know how to even go a kit it though. This could be a lot of fun though. Looking around and 54r bass is easy to find for cheap too. I’ve just never gone down this road. Don’t even know how to go about getting dies or even a chamber reamer made.
 
Thisisyourcaptin said:
Now this has me thinking. I just don’t know how to even go a kit it though. This could be a lot of fun though. Looking around and 54r bass is easy to find for cheap too. I’ve just never gone down this road. Don’t even know how to go about getting dies or even a chamber reamer made.
Click to expand...
Manson reamers or Pacific tool &gauge can get a reamer made for you, and lee or pretty much any of the die makers can custom make dies for you. You could also make a neck sizing die by cutting down a 357 die (or reaming it) to just the neck length since headspace measures off the rim for a x54. A 35x54mm sounds like a great project, and I'd bet its been done before, I would like to punch one out to 375 myself. I just missed the boat on cheap moisin rifles...
 
Thisisyourcaptin said:
After doing some research. It seems that your are right. It’s going to be quite the undertaking. Frankly the hardest of which is finding someone to either weld and machine the bolt or even just machine it. The barrel is the easiest part of all this it seems. I have found a few threads on other forums and they all seem to point to making it a 45-70 as the easiest of them all. BUT you still have to work the bolt face. Not many gunsmiths find that a worth wile prop. I guess I was hopping it would be easier. As in a few more gunsmiths out there willing to under take it. I can build this as a 7.62 sportier for a much cheaper proposition. maybe that’s the route I should take.

The 7.62x54R is no slouch of a round. With the right barrel and reload data it is something to work with. I need to do something on this. I really dont want to invest in more reloading stuff. While cheaper it just means more to learn. as a pilot I’m only home two maybe three days a week and I’d rather spend my time with stuff I know or shooting. 45-70 isn’t out of the question just not what I really want.
Click to expand...

Considering rimmed cartridges, my first thought was .30-40Krag and .303British which, along with 7.62x54R, are dimensionally pretty close. They come from the same time frame. As an updated hog hunter, with any of the three, you could probably work up a hard cast load at 200-220grs. .303 (.312"dia.) will get you a jacketed 174grRN @2400fps... maybe hotter but why. I know, not a .35Whelen, but probably more to work with within the capabilities of the action.
 
A possibility is the .338MarlinExpress if you’re going to rebarrel. The rims are close, and the .338ME is a SAAMI cartridge with available factory ammo.

When in early days of .338ME, shell holders and such weren’t available, I used 7.62x54 shell holders. Not exact or perfect, but close..

I’d personally stick with the 7.62x54. It’s not bad...
 
How do you convert an 8x57 Mauser to 9mm Luger? Turn the Mauser into cash and the cash into a Luger. It's just about the cheapest conversion you can do.

Still, a lot of people enjoy the tinkering part of the hobby, and if you want to do a project, I'd strongly consider the standard Mosin cartridge with .308 bullets. That gives you a lot more selection.
 
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