.303 British resized for use with Mosin rifles

May be this picture will be interesting for .303 British and 7,62x54R Mosin collectors.

In the end of 1919 Soviet Republic was in strong “cartridge crisis”
From 3 “carist” cartridge plant only Tula produced cartridges for Red Army. New plants in Simbirsk and Podolsk only start working and can’t supply adequate quantity of cartridges for Army.

In this situation, Soviets decided to resized a part of available stocks of .303 British Mk VII cartridges for use with Mosin rifles. Such cartridge alteration took place at Tula cartridge plant and new Podolsk cartridge plant in the end of 1919 and, probably in the early 1920.

The picture below show (from left to right):

  • 303 British cartridge
  • 7,62x54R cartridge
  • resized .303 british for cal. 7,62x54R
  • sectioned resized .303 British
  • bullet of resized .303 British and
  • case of resized .303 British fired from Mosin rifle

This just about defines “desperate measures” as far as small arms ammunition is concerned. The idea of someone actually firing a cartridge with a base as undersized as this and with the bullet most likely jammed into the rifling makes my blood run cold. A truly fascinating artifact. Jack

Not really desperate, the Austro-Hungarians were using 8x50R ammo in captured Mosin nagant M91 rifles during WW I, without any ill effects ( even given the Bullet dia,eter disparity, .324 Cylindrical to .310 Rifleong Groove.)
( “AZF” marked M-N M91 Rifles). and the Russians used 7,62x54R Ammo in M95 Austro Hungarian Mannlichers …completely undersized.

AS to the “resizing” of .303, WE have done this for re-enactments with SVT40 rifles, using FN * .303 Long Blank, simply re-sized in a 7,62x54R Die, and they fed, and fired without any problem.

Remember, the Chambers of the M91 rilfes were quite “ample”, Having been made for the cylindrical Bullet prior to 1908, and still able to use it after the introduction of the “LPS” ( Light, spire Bullet) after 1908, so a resized .303 would fit ( either with the case neck cut back or not) and fire. The Mosin action, of course, was amply engineered to counter any Pressure problems with such a “cartridge of fortune”.

Of course the ample quantites of .303 were both Ammo given with rifles to Tsarist troops, and enourmous reserves left at Archangel and Murmansk and other points of entry, remaining during the revolution. besides being Z"converted" during the Revolution and subsequent Polish-Russian War, a lot of unconverted ammo went to Spain (SCW) some 16 years later), and maybe even used during the 1941 defence of Moskow ( along with .303 from Estonia)

Interesting find,

Doc AV

WOW… thanks for the info…never knew that they did that… desperate times… desperate measures…

Great post and pics!
I imagine these are not very common? Would be a great addition to any 7.62 Russian or 303 collection.

Thanks, Treshkin.

Whilst I knew this was done, these are the first actual examples I have seen.


I find it hard to see how an untrimmed .303" case would fit in a 7.62mm M-N chamber. Years ago I converted .303" to 7.62 M-N by setting the shoulder back and sleaveing the case but they would not chamber until trimmed to length, 54mm M-N vs 56mm for the .303".

Of course, standard .303 British don’t fit in Mosin chumber, but mainly because of case schoulders:

Though it is possible to turn the bolt with some effort, as Russian soldiers did from time to time. The proof is .303 British cases fired of 7,62x54R weapons, which we find in trenches of WWI and WWII

Resized .303 British good fits in Mosin chamber because of squeezed case neck and mouth:

The part of this business that I find most unsettling is the grossly undersized case body. As long as the brass is good (as the example shown was) nothing too dramatic will happen, but when (not if) a weak or brittle case is fired in this setup the shooter has fire in his face. Jack

Jack, I guess the risk and consequences of not having any ammo to fire at the enemy far outweighed the risk to the individual shooter.

Alpine: I agree; that’s why I wrote “desperate.” Jack

Yes, you are right, Jack. All depend on the brass quality. On the first picture shown the fired case with rupture on the neck. Taking into account that .303 British case has a thin case body comparatively to 7,62x54R, we can assume that powder gases can move back from the chamber to the bolt. May be the additional resizing of the case neck without folloowing anneal (because cartridges was resized in loaded condition) may lead to heightened shortness of the brass in this part of case, and correspondingly - to inclination to split formation

I have read somehwere online about .303 rifles being reamed to chamber 7.62x54R Cartridges. These were supposedly used in Russia during WW2.