I did just the opposite a few years ago when I had a 30-06 and a 243 with ammo on the shooting bench at the same time. Fortunately for me, I had 243 ammo in the '06 rather than a reversal. When I pulled the trigger, the report and recoil was obviously wrong. The neck and part of the shoulder was gone as I recall and I was pale for a few minutes. The shooting bench was then cleared and I adopted a new shooting practice... nothing on the bench except what is actively being shot.

Ian

picture of a 9mm bullet fired in a 7.62x25mm chamber.

This was done by an someone else in one of my CZ52s.
These are weak pistols that blow up with the slightest overload, so there must have not been and increased pressure spike. He made a 30 cal hole in the target.

He also shot a 7.62x25mm round in a 9mm chamber, and that jammed that gun.

I had a similar expierience a few years ago when a friend of mine and myself were sighting in our rifles after having rescoped them. Mine is CZ 527 in .223 and my friend has a Steyr in .222, so you can guess what happened. I accidentally loaded a.222 cartridge in my .223, fired the rifle and noticed that the sound was different from previous shots. I opened the bolt, as easy as always, took out the empty case, studied it but could not find anything wrong with it until I took a closer look at the bottom. It read .222 REM! The case had been completely fireformed. The rifle showed no damage which was confirmed by the gundealer I bought it from.
Last year I was at a shooting range where somone had fired a .243 in a .308 rifle. When he ejected the case, it had been split. The neck part was gone and had got completely stuck into the throat of the barrel. Later I heard that this man had to replace the barrel because the brass had been completely welded into the barrel material.

I learned to keep my empty cases completely separate per caliber,never load more that one caliber in one session and check every single reloaded cartridge before I put them in the box.

The damage you describe speaks well for the Mauser design..Most I have seen did about what you describe but stayed in one bellowed out piece regardless of the power behind the explosion...

Not so the M-70s that I have seen blow, the fragmented sending chunks in every direction and ended up in serious injury to everyone around them..

Not to degrade the M-70 or the Mausers, both are the finest built, the fault lies in human error in almost every case, and for the most part should never have happened...

All my rifles are either Mauser or M-70 pre 64 and I have never had a gun blow or even damaged, they both have a built in safty factor on pressure, but a mistaken case full of Bullseye is hard to stop!

Jeffe,
the 98 Mauser handles gas better than about any rifle, It is the M-70 Win. that lets the gas come back to the eye..This is due to design changes that Win made over the Mauser...no gas shield on the M-70 to deflect..

Zach,
in any event except a primer, the mauser handles gas pretty well...

take the bolt apart...

jeffe

Jeffeosso-



Interesting combo, that .308 in a .257 Wby Mag



We had a local couple commit exactly the same error at our range last year during our public "Sight-In Days" just prior to deer season.



In this instance, he was shooting a .257 Wby Mk. V; she was shooting a .308 in what I believe was a Vanguard. She tired of shooting and wanted to quit. He harrassed her into sitting down and shooting his Wby. Both the .257 Wby fodder and .308 Win ammo were on the bench.



When she touched off the Mk V Wby, the action froze shut, 4 inches of the left side of the stock disappeared beginning at about the rear of the front receiver ring, and the magazine floor-plate was badly bent. The barrel had to be removed to open the bolt.



Removal of the barrel showed the bullet had not entered the rifled part of the barrel at all. It was stuck in the throat (actually, more soldered than just "stuck").



Needless to say, she was a bit hot at her husband, who I suspect slept UNDER the dog house for the next few months.



She was not physically injured, primarily because she had her left hand holding the rear sandbag benchrest-shooter-style. Otherwise, her wrist would have been exactly parallel to and up against where the stock disappeared. That could have been rather bloody and nasty.



The .308 bullet in the .257 Wby bore is exactly what was said earlier here...a plug.



Alberta Canuck

Ackley did a whole series on this, as written in the handloaders guide vol I and II, on these things..

jsut some of my thoughts on the subject...

intial pressure was not "high' rather not contained... when the bullet fired, loads of energy went into reforming the 308 brass... THEN, when the entire chamber was full of pressure (may have erupted the brass) the gas and bullet had no where to go but into the barrel... which would have been a CORK in a .257 vs .308 barrel. THEN things got messy, as the preassure would have SPIKED in the chamber, causing structual failure of the brass.. and ruining the firearm.

there's an explozed 257 webby at carter's country, that a 308 was fired in... the gas was handled, the stock split, yet the barrel, action, and bolt seem "fined".. gas handling, so to speak...

on mausers, I am always worried on gas handling, as IF the primer is pierced, the gas comes directly back into the user's eye/cheek via the bolt

ackley as did extreme pressure testing on several actions.. with the jap 6.5 being the most survivable... as it was the softest, it did not cause "steel rain"

just rambling
jeffe