Unknown ctge

EOD, I think it does interchangeable. Because when Serbia in 1914 received aid of 120.000 M-N rifles from Russia, in this delivery was both model, but all ammunition was M-91 , with round bullet, besides some M-91 rifle have arsenal adaption with new rear sight for S bullet. In my collection I have M-N rifle from Tula arsenal made 1904 , but with new rear sight.

If the chamber was cut for any “high shoulder” version of this cartridge every “long necker” cartridge must fireform to the new configuration. Since a chamber cut for the long neck version can’t chamber the standard version due to the position of the shoulder, they must have changed chamber dimensions too.

My long neck case is fired but still has the long neck, so the chamber was right for this case and not cut for later versions.

Is there any documentary evidence that the 7.62 m/m Mosin rifle has ever had any chamber other than the one well known for the last century and more? Jack

Howdy DreamPhoto
it seems to me that your rifle with the new sights means this cartridge is not interchangeable. If it was why change the sights?

The rim thickness on the M-91 cartridge seems to be thinner that the later models so it might well not give feed or headspace problems, and the newer model cartridges may well chamber and cycle through your weapon, but if the sights need changed, it is not 100% interchangeable.

Perhaps this is what EOD means? Or perhaps he can expand on the ‘why’ of it ?

This has been an interesting thread. I believe Vince Green offered a very valid caution about worrying too much about the case shape/shoulder dimensions on a rimmed rifle cartridge. I suspect that actual chamber dimensions for M-N chambers varied considerably from those of actual cartridges, and probably varied over time and perhaps manufacturers.

Long ago I had am Enfield Jungle Carbine I fired quite a lot. The chamber was so much larger than the 303 cartridges I was buying (mostly Norma) that I could only neck resize my fired empties when I reloaded them. If I full length resized the cases, some suffered head failures on the first reload and quite a few on the second. I threw away all the cases I had resized. The shoulder of the fired cases was considerably different from the new cases. There was a good deal of bulging just above the case head. I was later told that this was not unique to the Jungle Carbine and was deliberate to allow dirty ammo or even ammo with some mud to feed in combat. I suspect that the same situation exists in the case of M-N rifles. This chamber “slop” would make shoulder dimensions much less critical than it is for rimless cartridges.

Lew

Howdy DreamPhoto
it seems to me that your rifle with the new sights means this cartridge is not interchangeable. If it was why change the sights?

The rim thickness on the M-91 cartridge seems to be thinner that the later models so it might well not give feed or headspace problems, and the newer model cartridges may well chamber and cycle through your weapon, but if the sights need changed, it is not 100% interchangeable.

Perhaps this is what EOD means? Or perhaps he can expand on the ‘why’ of it ?[/quote]

Hello PetedeCoux,
sight was change because lighter S bullet, with higher Velocity. Except this and new gunpowder , cartidge M-1908 was same like M-1891 ctg.

  1. For Alex :

Are the shoulders on the tree models at the same position?

For me it is yes (based on specimen and on Russian drawings)

But, if I understand well, you said no before.
Could you please show evidence (drawings or pictures) ?

  1. For Pivi:
    If I understand well you have a German fired case with the shoulder well below a regular Mosin rifle.

If it was fired in a regular Mosin chamber the shoulder would have go up due to fireforming.
Therefore we can conclude it was not fired in a regular Mosin riffle
Do you agree ?

  1. Till I don’t have these both answers I can’t go further.

Thanks
JP

JP,

Yes. But my fired sample is russian, not German. Headstamp is " T 16"

JP,

Yes. But my fired sample is russian, not German. Headstamp is " T 16"

Ok, but your fired case has a low shoulder, right ??
JP

Yes, lower shoulder, longer neck.

Ok.
This prooves there were riffles chambered for a low shoulder, right ?

Therefore now we wait Alex confirming the three models of Mosin have a different shoulder heights (and giving dimensions).

If one model of Mosin ctge has a low shoulder it would be logical the gun to be chambered for a low shoulder ctge, and in this case the DM 17 ctge is a Mosin ctge.
And we can wonder why Russian have not assured compatibility between the old ctge model (which will not chamber in a new model riffle with a low shoulder chamber).
And why they have changed again after for a high shoulder ctge.

If the tree models of Mosin ctges have the same height I have another suggestion.
But I 'm waiting the answer from Alex

JP

If

jeanpierre, thanks for your trust in me but here are some people who should know much better than I ever will + I am drowning in work at the moment.
Maybe anyone else could show the different cartridges and elaborate on the neck shapes whe have observed over the years. The cartridge is for over 110 years in service now!

I’m sort of losing the thread somewhat. Regarding interchangeability of cartridges, I would propose that interchangeability means simply that a cartridge can be chambered and fired in any rifle intended for that cartridge, regardless of bullet weight or profile, or what kind of rear sight is needed. For example the .30-'06 cartridge can be chambered and fired in a .30-'03 chamber (but not conversely).

I am sure that over the long duration of the production life of the M-N rifle there have been variances in chamber dimensional tolerances and maybe even chamber shape, but I cannot imagine any government fielding any combat rifle which would not safely chamber and fire any cartridge from any source and any production date originally intended for use in that rifle type. To do otherwise could be disastrous. So are we talking about just sloppy chambers (which are commonly encountered) or contending that fundamental differences in cartridge/chamber dimensions exist which would preclude full interchangeability among all rifles and all ammunition of all ages?

The initial topic was very simple:
Is the DM 17 ctge shown at the beginning a 7.62 Mosin ctge or not ?
(I don’t ask if such a ctge can be fired in a Mosin Rifle)

Alex said the position of the shoulder changed during the years.
(change as important as for the DM 17 ctge)

With all the people on this forum collecting this caliber it would not be difficult to show me factory drawings proofing it.

It is just a single question for my knowledge.

JP

jeanpierre, easier said than done, and when looking at all available material you will not find two identical drawings (as for measurements).

Despite my limited time this is done only for you:

Measurements which are not metric are in “lines”. The Russian line is connected to the inch. So for example 4.2 lines are .42".

Hello Alex,

It was not necessary to spend your time posting all these drawings, they are the same that the ones I have .

Perhaps you thought they were helpful to other people.
But it seems they had them already if we see the absence of thanks.

I can only say again what I said before :
If we compare SFM drawings of Russian ctges (models of 1890, 1908 and 1930), we can see the shoulder is at the same position (varying from 38.5 to 39.70 from the head).

This makes 1.2 mm variation in the worst case.

Nota :the only SFM drawing where the ctge shoulder is lower than for the other ones is the number 7017.
First is an error (all the drawings from before and after this date are in the tolerances , and I think they confuse the total length with the length before rim) ,
And secondly it referes to the model 1890 and not 1908;

If we look now on the non SFM official Russian drawings of 1908 and 1930 ctges we see there is no difference in chambers, and no difference in the shoulder of the ctge.
Furthermore these dimensions are compatibles with the dimensions given by the SFM drawings

Nota: Two things are surprising me:
The fact that nobody didn’t even bother to check the drawings you gently put in this topic to check if the dimensions were different or not.

The fact that nobody collecting Mosin ctges didn’t even bother to check his collection and put pictures of samples to show if some russian ctges had such a short neck or not.

Anyway, perhaps some Russian ctges have such a low shoulder ??
I am not collecting such ctges , therefore I don’t know.
And if yes, which year? Which hstp ? And why ??

Coming back to the initial topic about the big difference in shoulder position, and without knowing if some Russian ctges have such a low shoulder, I am wondering why the shoulder is so low.

7.62 Mosin ctge was already an old ctge in 1917 and well known by German companies.
The DWM drawings show a regular shoulder, not a low one.
And when I check my reference DWM ctge with 378 number on it, the shoulder is also normal.

MosinDWMbis

mosinDWM

Perhaps somebody on this forum could explain that to the people collecting such ctges.

About me, I don’t collect anymore this kind of ctges, I have already my own explanation, therefore it is not very important if nobody answers.

JP