Hi,
Hope this is the right forum for my question.

I have been looking at optional calibers for the m/1895 Winchester. One of the problems with the older guns is that they do not withstand the modern loads' pressures. So much so, that Winchester itself dropped the .30-06 from their lineup for this model. The modern variants do withstand higher pressures, though.

I am curious about the original pressure of the .30-06 and the 7,62x54R.

You see, if we look at the maximum pressure the rifle can handle, we see that the 7,62 exceeds that. Yet there were some 300000 of these manufactured for the Russian army... So I started to wonder if the pressures back around 1906 and 1916-1917 have been lower than they are today.

Apparently, the maximum pressure that the (old) guns can handle, is unclear. 46000 and 47000 psi has been quoted.
The CIP max. pressure for the 7,62x54R is 3900 bar, i.e. 56560 psi.

I am sure any 1895 can handle the pressure of any cartridge you can put in it.

The old 1885 rifles are worth too much money to re barrel.

Calculating stress:
a) The cross sectional area of the inside diameter of the brass cartridge case is multiplied by the peak chamber pressure to calculate bolt thrust.
b) Calculating hoop stress on the barrel walls is [The peak pressure in the chamber]/[[2][ the wall thickness] ]
That is the formula for thin wall hoop stress, but can be corrected for thick wall with Lame's formula and corrected for open ended [breech] with Roark's Formulas
http://www.amazon.com/Roarks-F...Warren/dp/007072542X

Guns will not blow up per those calculations. I have tried to blow up many guns, and they are harder to blow up than I would calculate. I think there is a dynamic yield strength at 1 ms that is higher than the static yield.

To get a feel for blowing up guns, put a Glock barrel in the fire to wreck the heat treat. Then overload the pistol until the primer are falling out of the brass. Measure the chamber wall thickness ~ 0.08".
Look up the strength for soft steel ~ 100ksi.
Now calculate the stress if the primer falls out at 65kpsi. That barrel should have burst, right?

Now look at a rifle.
Notice how hugely thick the walls are, in contrast with the pistol you just failed to blow up at the limit of the brass.
No point in doing any calculations on hoop stress in a rifle, is there?

My 1895 in 30-06 had quirks that were not desireable but never produced any damage or injury.
Ejection of fired contempory 1970s commercial ammo was a little difficult. A spent case out of it would not rechamber. FL sizing was absolutly necessary. The cases also stretched badly. If I loaded for one today it would be done at 30-40 performance levels only.

Better still I think I would just hang it on the wall or take it to the range once every two years to stimulate inquireing eyes. roger

If it is a genuine 1895, you could sell it for enough to buy 6 modern .30-06. Just do it before the Obama effect is over.

The problem is not one of potentially blowing your gun up. It is one of potentially having a brass failure in an action that does not have front locking lugs.

Because of the relative "looseness" of the Model 95 action, and the compression (shortening) of the bolt itself under high firing pressure impulse, there is more likelihood of having a brass failure than when firing the same case at the same pressure in a bolt action.

By brass failure, I don't necessarily mean blowing the head off the case or splitting it lengthwise, though either could happen very, very infrequently. Primarily, I mean such things as increased possibility of expanded primer pockets and resulting primer leaks, etc.

Anyway, there is a very very tiny but still very real increased chance of getting a brass failure which will set loose high pressure gas in the action. That in turn can cost one some eyesight.

It is up to you to weigh whether the higher pressure loads are worth the risk for your use.

Thousands of folks beat the odds every day...they do not include me. I, like Roger, load to lower levels.

A. C.
Truer words were never spoken.
"Thousands of folks beat the odds every day...they do not include me."

muck

quote:

I, like Roger, load to lower levels.

I have said this before - the 30-06 is a plenty powerful cartridge. Is there any reason not to use reduced loads? (I am now down loading my 303 Brit after realizing just how plenty powerful even that cartridge is!) I am talking starting loads which are quite mild, really. The reduced recoil being the motivation. (Muzzle breaks are now the order of the day - 'Quiet Muzzle Breaks' - that is.)

quote:

Apparently, the maximum pressure that the (old) guns can handle, is unclear. 46000 and 47000 psi has been quoted.
The CIP max. pressure for the 7,62x54R is 3900 bar, i.e. 56560 psi.

Apparently, the old pressures were quoted in psi when in fact, they were CUP. (An error in the CUP interpretation which was discovered later?) So there is no contradiction?

The 95 Winchester (and the 03 Springfield)
had chambers with necks large enough to accept
8x57 Mauser cartridges. It wasn't the larger
bullet that caused the problem. The neck was
pressed into the bullet keeping it from leaving
the case. Winchester dropped the 1895 because
of blowups with 8mm ammo.
Good luck!