Yesterday's Weapons Forums

I have a 1933 Hex mosin receiver here. Been thinking about making it into a wildcat 375 X 54r
Don't know why but it intrigues me the thought of putting cast 250-350 grain boolits through it.

Thoughts?

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It's 5 o'clock and it's watermelon time.....................
because you can't drink beer & load rockets - TXPete

Consider something using the 45-70 rim - which would not be too different from the Russky rim. There's the 33 Win - I'll contribute the dies if you go that way. Feeding wouldn't such a pain with that cartridge. 338 bullets work right from the box. I've formed brass from 45-70 starting with 40-65 FL sizing. Cramb the case full of cream o' wheat & FL size in 33 Win die.

A 40 cal would be cool, too 40-65/40-60. Brass is a two pass conversion from 45-70.

One of the Sharps bottlenecks - 44-77 Rem 40-70 Sharps...

Dig out yer Cartridges of the World and crunch some numbers for the 33 Win conversion. I think it's do-able. SW

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Slava Ukraini!!

Somewhere around here I have a book with information on the various Finn wildcats based on the 7.62X54R case. They came up with a wide range of such cartridges, mostly using barrels or barrel blanks made for the various mauser and other rifles they'd used in more limited quantities, such as Swedish and Carcano 6.5 and Mauser 7mm, even a few using .22 barrels.
I don't remember much about that article but it was likely they spliced barrels in the same manner used by Australian gunsmiths when adapting the Lithgow actions to smaller or larger bore wildcats.

Seems like there were 9mm or slightly larger bores among these, and theres a 9X53r version based on the 7.62x54r used in the Medved sporting rifles intended for bear and large bodied game animals in Russia.
You don't hear much about the Russian largebores since in the old Soviet only a few families of professional hunters, commisioned by the government for predator control and such, were allowed to own high powered rifles for sporting use. Everyone else was restricted to small bore rifles and shotguns.

PS
There is a Finn 9.3X53r thats similar except for bore size. Perhaps Lapua has reloadable brass for these.
http://www.municion.org/9_3/93Finnish.htm

That is actually kind of what I was after but just a little larger from .366 of the 9.3 to .379 of the 38-55 which I already have molds for

_________________

It's 5 o'clock and it's watermelon time.....................
because you can't drink beer & load rockets - TXPete

Theres also a .375X52R based on the 54R case. It was developed by custom rifle maker Jyri Jalonen to be used in Double rifles built on the Valmet 412 action.
The .375X52R has a shorter neck and larger powder capacity. Cases require fireforming to fill out its more spacious chamber.

According to "Children of the 7.62X54R" by Janne Pohojoispaa, the cartridge when loaded with 57 grains of Vihtavuori N540 under a 270 grain bullet produces a muzzle velocity of 2297 FPS.
Photo accompanying the article show the shoulder is moved far forwards and the neck is left little more than half its original length.

Wonder what kind of pressures it generates. Have to stay within the rated 40-45k of the mosin action

_________________

It's 5 o'clock and it's watermelon time.....................
because you can't drink beer & load rockets - TXPete

If the cartridge is almost solely meant for use in modern custom double rifles the recommended loads may be a hair too hot for older MN actions.
Also from discussions of other European cartridges I get the impression that loads worked up for use in artic climes can generate excessive pressures when used in warmer regions. A load safe for hunting in Finnland may be too hot for hunting boar in Georgia.

Best to work up your own loads carefully, and not depend on previous loading data.
The Powley Computer might help.

I'd go with the blown out case of the 375X52r, the greater case capacity would allow a wider selection of powders and loads, and a stronger shoulder.
Not likely to find either cases or reamers available so it would be custom work from get go.
Might as well give your wildcat a personal touch and ream the chamber along Ackley Improved lines.

I've had a Hex receiver here for awhile, I thought at the time that a part octagon barrel with quarter rib and express sights would go well with this action type.
The MN magazine and feed allows alot of leeway in cartridge profile, but the MN rifles successfully converted to .30/06 required that the magazine box have its sides straightened. This is something you should look at before chosing a case with the shoulder set forwards.

Probably best to start out with a 9.3X53r chamber and .375 bore, being sure the chamber neck has enough clearance, then later on you might freshen the chamber out to 375x52r if you want more performance.

The large bore and case capacity would lend itself to highly effective cast bullet loads, as well as some real go getter heavy game loads with jacketed bullets.

PS
A .357-358 bore would allow use of a chamber insert in .38 special or .357 magnum for use on smaller game like Turkey, or downloaded for rabbit and squirrel.
I've made up ultra light round ball loads in .38 that had about the same velocity as a wrist rocket sling shot, and report no louder than an air rifle.
I'd had a .357-.303 wildcat on my list of possibilities for some time now.

When I was over in Finland I shot a 9.3x53R Winchester model 1895 which was converted from 7.62x53R. It shot real well and I noted they bore out the orignal Winchester barrel to 9.3 caliber.

A friend who hunts moose in Sweden says that the 9.3 caliber bullet goes right through moose over there. 9.3 is a real nice caliber. I have four older Swede Husky guns chambered for 9.3x57 and 9.3x62. All of them are tack drivers.

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"We sleep safe in our beds because rough men stand ready in the night to visit violence on those who would do us harm."
George Orwell.