Accidentally firing a 8mm Mauser in a Model 70 .06

[Curator]

Commercial American 8X57mm ammo is designed to work at the lower pressures of the M88 Mauser rifle that "may" still have the .318 bore diameter. Not only is that particular model mauser comparatively weak, but standard 8mm bullet diameter is .323. American ammo manufacturers load a very soft/thin jacketed bullet precisely because it might be fired in one of these. While not recommended, firing one commercial American 8mm mauser cartridge in a well made modern .30-06 rifle should not damage the rifle

 

[NCsmitty]

The boy was lucky that he shot the anemic US 8MM factory loads and not some hot German or Turk surplus rounds. The results may have been much different.

NCsmitty

 

[skeet king]

I've accidently chambered and fired a 223 out of my ak, everythings fine

 

[Float Pilot]

He was able to chamber and fire it because while the 323 caliber bullet is larger in daimeter, the 30-06 case and thus the chamber is longer than the 8x57mm by about 5mm.
Basically the bullet had a ways to go through the remaining chamber, ,lead and then into the rifling.
So the bullet was being swadged down en-route.

The big danger here is not blowing up your model 70s, but that escaping gas from the incorrect brass could jet out and ruin an eye.

If for some reason the rifle started shooting better after this incident, it may be time to give it a real good bore cleaning with some JB bore compound.

 

[Vern Humphrey]

I've accidently chambered and fired a 223 out of my ak, everythings fine

It's one thing to fire a smaller bullet down a larger bore, and another thing entirely to do the reverse and try to drive a larger bullet down a smaller bore.

 

[Jeff F]

I know of a .270 that had a .308 round chambered and fired. No damage was done to the gun or shooter. I have also herd of the same thing happening and the gun coming apart. Be very careful not to get ammo mixed up.

 

[TehK1w1]

The boy was lucky that he shot the anemic US 8MM factory loads and not some hot German or Turk surplus rounds. The results may have been much different.

NCsmitty

I agree, if that had been turk surplus the result might very well have been much worse.

 

[ThomasT]

Okay. My granfather was a gunsmith in the 50s-70s. He was friends with P.O. Ackley and bought a lot of barrels from him Including one barrel chambered for 35 Whelen with a 30 caliber bore.

I have a letter writen to my GF by Ackley stating that as long as the case matched the chamber it was OK to fire a 35 caliber bullet down a .308 barrel. My GF screwed the barrel on a 98 Mauser and shot the gun with no harm.

The danger comes from shooting a case that does not fit the chamber. At Alpine shooting range in Ft Worth Tx there is an exploded rifle on the wall. It was blown up with an 8mm Maused fired in a 30-06 chambered gun.

Like some have stated I also sort of doubt he shot an 8mm. If he did he got lucky. You should have left the range right then and bought a powerball ticket. It was your lucky day.

If I knew how to scan in and post it I would post the Ackley and Phil Sharp letters that I inherited from my GFs estate. I knew my grandad was really into guns I just had no idea he was in touch with and seeing those kind of people.

If you remember there was an article in Rifle Magazine a while back about a man with a Jap Arisaka rifle he rechamberd to 30-06 but it still had a 6.5 bore. He fired it several times with no harm. He took it to his GS because it kicked too much. The NRA tested the gun and said the same thing as Ackley about the case fitting the chamber.

 

[jim in Anchorage]

This is all documented in the Ackley series of books.[I can,t find mine,I just moved and can,t find ANYTHING] He did a number of experiments with this over size bullet idea,like rechambering a 30-06 to 35 and leaving the bore alone. No failures.

 

[ThomasT]

Well Jim I did not know that. Thats the first I have heard of an Ackley book and I have posted this twice before. Thanks for the info.

 

[jim in Anchorage]

Its actually 2 or 3 books. Hand book for shooters,or some thing like that. When I find mine I will post more info. I bought mine 30 years ago from Brownell's,so it may be out of print. Great reading-they had a lot of fun in the Ackley shop circa 1940's.

 

[jim in Anchorage]

OK I found one. Handbook for shooters & reloaders,volume 1,by P.O. Ackley.I don't see the oversize bullet experiments in here,so it must be in V II. Mine was copyrighted in1962,and printed in 1985. Again make the effort to find them,great reading.

 

[bonza]

I know it's a whole different kettle of fish, pressure-wise, but there was/is a company in Australia that was selling .22LR chambered rifles with a .20 caliber bore. The bullets extruded upon firing creating an elongated .20 caliber. They may also have done the same with .17 caliber barrels, too.

 

[Slamfire]

If you remember there was an article in Rifle Magazine a while back about a man with a Jap Arisaka rifle he rechamberd to 30-06 but it still had a 6.5 bore. He fired it several times with no harm. He took it to his GS because it kicked too much. The NRA tested the gun and said the same thing as Ackley about the case fitting the chamber.

The article about the Japanese rifle was from back in the 50's. A couple of points about that incident.

They guy who reamed the 6.5 chamber out to 30-06, while he reduced the pilot size to fit in the bore, he at least did not mess up the reamer neck dimensions. The 30-06 case neck had room to expand.

The American Rifleman showed before and after pictures of the 30 caliber bullets fired in that rifle. The 174 FMJBT were swaged and extruded down the barrel. Without a doubt that is what happened with the 8mm bullets fired in the 30-06.

If the case neck is pinched, the most likely outcome is pressures so high that the case gets blown.

Another characteristic of the Type 38 rifle was the unusual amount of case head support the Japanese built into that rifle.

As stated before, the case is the weak link. Develop pressures high enough to blow the case, and what happens afterward is very unpredictable.