7.7x58 or .30-06 or what?

[Dutchman]

So, this guy asks if I want a box of once-fired Norma 7.7x58 Arisaka. Sure, send 'em over.

What's wrong with this picture? (I said). Well, duh. Somebody rechambered a Type 99 with a .30-06 reamer and then fired 7.7x58 Norma ammo in it and didn't notice.....

On the right is my handload 7.7x58 with 311299. On the left a normal .30-06 Springfield.

http://images25.fotki.com/v903/photos/2/28344/157842/ari1-vi.jpg

Dutch

[jonk]

It blew out the brass nicely. Sometimes you can get head seperation doing that if you don't fireform properly. The guy is lucky that didn't happen.

[madsenshooter]

So that's where the cases went from a box of Norma 7.7 Jap brass which was full of 30/06, that some guy gave me! just kidding, certainly no connection. But it's true that a guy did give me a box like that once, that was in Ohio. Wonder where he headspaced the case you've pictured, perhaps on the bullet. I don't see any sign of incipient head separation.

[runfiverun]

i have one somebody chopped off the bbl re-threaded and rechambered in 300 savage with the original 312 bbl.
hope the original owner was a reloader,it took me three days to figure out what case it took.
but it does okay with 313 boolits.

[Cactus Farmer]

Anneal them and run 'em thur your 7.7 dies. You'll have some good brass.

M-1 garands will shoot 308 match ammo and function well,but it sure makes funny looking brass cases.

Any rifle with a strong extractor will allow shooting "short" ammo. i heard a story about a fellow who shot 300 Savage in a 308 bolt gun,he called 'em "shorts".

[1874Sharps]

I must admit that once I grabbed a box of 300 SAV reloads that I mistook for 308 WIN to shoot in a Mauser bolt gun. Well, they fed and shot just fine and there was not one indication of anything wrong until I happened to look at the headstamp and realized my error and ceased fire. It appears that the shoulders are very close and so there was not a big headspace problem. The pressure level of the 300 SAV rounds were also substantially less than that of the 308, so that was a good thing. I would not recommend doing what I did, but I got away with it with fingers and eyes and gun intact.

[Dutchman]

But it's true that a guy did give me a box like that once, that was in Ohio.


I use to live south of you in Pulaski County, Indiana. Off Hwy 421 down the road from the Sandhill Crane Preserve. Medaryville. The guy who gave me these was in... Ohio.


Dutch

[rhbrink]

Anneal them and run 'em thur your 7.7 dies. You'll have some good brass.

M-1 garands will shoot 308 match ammo and function well,but it sure makes funny looking brass cases.

Any rifle with a strong extractor will allow shooting "short" ammo. i heard a story about a fellow who shot 300 Savage in a 308 bolt gun,he called 'em "shorts".

Cactus Farmer I have a question for you, are you talking about shooting a 308 in a 30-06? A couple of years ago I was helping a friend sight in his deer rifles, he had a 308 model 70 newer one and also a model 70 '06. He would shoot one a few rounds and then pick up the other and shoot it while the first one cooled off. I should have been watching closer but the guy is a good shot and seemed like he knew what he was doing. But things happen, pretty soon he shot a 308 shell in the '06. I was sitting next to him across the bench spotting and thought the gun blew up! He did too! Niether of us got hurt but it blew the floorplate off the stock split the stock from the magazine forward. The 308 shell looked like a extra-extra long 45ACP. I didn't intent to hyjack anybodies thread but was just curious cause it a very bad experience for both of us and one that will not be forgotten

[Cactus Farmer]

I've seen a lot of 7.62x51 match ammo shot in M-1s while I was in the service. People would scrounge ammo from service members and "assume" if they shot it it would fit theirs too. Trouble was all the USAF match grade guns were reworked M-1s that had 308 barrels. Match grade ammo is good brass and sports the annealed neck colors which could be the reason they didn't cause any dificulties.
After the matches we would go thru the brass and sort out the 30'06 match from the 7.62. There wasn't a lot of 30'06 but we wanted to save them for personal reasons. I'm still shooting most of it!
You would come across a fair amount of those 45XL cases........funny looking things. The soft military brass must have sealed off good enough......never saw a broked rifle come off the range,or for that matter any bloody shooters either.:coffeecom

[TCLouis]

This makes me think, I have a nicely sporterized Type 99 around here someplace that was rechambered to "something".
I need to cast the chamber and do some measurements.

I know several guesses of what it isn't, just not a hint of what it is!

[Buckshot]

Cactus Farmer I have a question for you, are you talking about shooting a 308 in a 30-06? A couple of years ago I was helping a friend sight in his deer rifles, he had a 308 model 70 newer one and also a model 70 '06. He would shoot one a few rounds and then pick up the other and shoot it while the first one cooled off. I should have been watching closer but the guy is a good shot and seemed like he knew what he was doing. But things happen, pretty soon he shot a 308 shell in the '06. I was sitting next to him across the bench spotting and thought the gun blew up! He did too! Niether of us got hurt but it blew the floorplate off the stock split the stock from the magazine forward. The 308 shell looked like a extra-extra long 45ACP. I didn't intent to hyjack anybodies thread but was just curious cause it a very bad experience for both of us and one that will not be forgotten

............What would have caused that? Seems if the 308 would expand enough to seal the chamber, then that would be it, no? I've seen 308's fired in 30-'06 chambered bolt guns a couple times. One instance was only 2 shots before the shooter noticed. The other had the shooter running almost a full 20 box through his rifle, before the guy at the bench next to him noticed the odd brass on the ground and put 2 & 2 together.

..............Buckshot

[NickSS]

A bunch of years ago a guy sold me a 6.5 arisaka that had been chambered to 7X57 mauser and had a bishop stock on it as well as a cheap scope. He told me it was rebarreled to a 7X57 barrel and it came with a couple boxes of Norma 7X57 brass as well as half a dozen loaded rounds. The brass looked fine so I reloaded it and went to the range to fire my new toy. I noticed during firing that the gun kicked harder than I thought a 7X57 should There were not other indications of problems and accuracy was not bad as I recall. When I got it home I cleaned it and when I looked down the bore from the rear I noticed that the chamber looked funny where it met the rifling so I looked further and found out that it was the original 6.5 barrel that someone ran a 7x57 reamer into. I am glad those arisaka's are strong.

[rhbrink]

Buckshot I don't know and can only guess that maybe the 06 chamber was a little bit long? Anyway it didn't seal and there was a major gas blowby? As luck would have it the guy shooting had his off hand back by the rear bag and it was cold, we had some coats on. If he had placed his hand forward on the forearm or around the floorplate some serious injury would have resulted. As best as I can remember this was with factory ammo and a factory rifle. Just can't be too carefull.

[MT Gianni]

A bunch of years ago a guy sold me a 6.5 arisaka that had been chambered to 7X57 mauser and had a bishop stock on it as well as a cheap scope. He told me it was rebarreled to a 7X57 barrel and it came with a couple boxes of Norma 7X57 brass as well as half a dozen loaded rounds. The brass looked fine so I reloaded it and went to the range to fire my new toy. I noticed during firing that the gun kicked harder than I thought a 7X57 should There were not other indications of problems and accuracy was not bad as I recall. When I got it home I cleaned it and when I looked down the bore from the rear I noticed that the chamber looked funny where it met the rifling so I looked further and found out that it was the original 6.5 barrel that someone ran a 7x57 reamer into. I am glad those arisaka's are strong.

6.5 x 57 is a well know European cartridge. Ackley had some data for it.

[StarMetal]

A bunch of years ago a guy sold me a 6.5 arisaka that had been chambered to 7X57 mauser and had a bishop stock on it as well as a cheap scope. He told me it was rebarreled to a 7X57 barrel and it came with a couple boxes of Norma 7X57 brass as well as half a dozen loaded rounds. The brass looked fine so I reloaded it and went to the range to fire my new toy. I noticed during firing that the gun kicked harder than I thought a 7X57 should There were not other indications of problems and accuracy was not bad as I recall. When I got it home I cleaned it and when I looked down the bore from the rear I noticed that the chamber looked funny where it met the rifling so I looked further and found out that it was the original 6.5 barrel that someone ran a 7x57 reamer into. I am glad those arisaka's are strong.

You are lucky for sure that you didn't get hurt. When I get a new rifle I always inspect it, clean it, and slug the bore/groove. Better safe then sorry.

By the way, how was the accuracy with that mixed matched combo?

Ackley reamed a 6.5 Jap with a 30-06 reamer and fired 06's in it and it didn't give up the ghost.

Joe

[madsenshooter]

Ackley may have done that too, but while going to college I got into the back issues of American Rifleman. It was in a 1959 issue that I read of some fellow doing the above, he killed several deer with the rifle even, then took it to a gunsmith wondering why it kicked so hard. The gunsmith sent it to the NRA Technical staff, who fired some more 06 through it. I imagine what saved the fellow was the fact that the head of the cartridge is completely surrounded by steel in the Arisaka, swaging the 30 cal bullet down to 6.5 would probably have produced enough pressure to rupture the case had the head not been so supported. I wonder how he ground down the pilot on the reamer? Dutchman my box of 06 in a 7.7 jap box came from Lancaster, Ohio. Pretty odd coincidence though.

[StarMetal]

Ackley may have done that too, but while going to college I got into the back issues of American Rifleman. It was in a 1959 issue that I read of some fellow doing the above, he killed several deer with the rifle even, then took it to a gunsmith wondering why it kicked so hard. The gunsmith sent it to the NRA Technical staff, who fired some more 06 through it. I imagine what saved the fellow was the fact that the head of the cartridge is completely surrounded by steel in the Arisaka, swaging the 30 cal bullet down to 6.5 would probably have produced enough pressure to rupture the case had the head not been so supported. I wonder how he ground down the pilot on the reamer? Dutchman my box of 06 in a 7.7 jap box came from Lancaster, Ohio. Pretty odd coincidence though.

I believe after Ackley did that test he said, which I find hard to believe, that after the initial engraving of the fat 06 30 caliber bullet that the pressure after wards wasn't as high as a standard 6.5 jacketed bullet. Now that's interesting. Maybe I read it wrong...dunno.

The Jap rifle does kind of have a hollow breech the bolt goes into to. The barrel at the breech end is shrouded.

Joe

Joe

[madsenshooter]

Arisaka ammo goes in up to rim, like a Krag.

[TCLouis]

NickSS

I would be willing to bet that what started out as a typical 6.5X50 and the lack of brass in the 60s required some gunsmithing expediency. Typically the solution was to run a 257 reamer in to rechamber with the result called 6.5X257 this probably became 7X57 with ignorance and passing through several sets of hands. The difference in the 6.5X257 and the European 6.5X57 is the same shoulder angle difference between the 7x57 and 257 Roberts. I know a little about the chambering as a matter of fact I plan to hunt with mine Friday morning. , We had two and one of the relatives of my ex relieved us of it while I was on active duty.
The only good thing that I know of from GCA68 was the requirement that a gunsmith mark the chambering of a rifle they built

[TAWILDCATT]

you should see what a 303 savage looks like after being fired in a lee enfield.

[Three44s]

A local widow hunted with her late husband's 300 mag.

She was not having good luck hitting things.

A friend of mine offered to help.

What he found was a box of 300 Win mags .........

......... fired in a 300 Weatherby

Three 44s

[rhbrink]

A couple years ago sitting around break time the subject of guns and shells came up one of the guy's walked over to his truck and brought back a box of fired ammo asking are these suppose to look like this? NOPE! He had been shooting 300 Win mag in a 300 Weatherby, thought a 300 was a 300, said they shot ok killed a deer with them. Cheaper too!

[Bret4207]

You guys are all mistaken. That's not a 7.7 fired in a '06 chamber. That's new, super improved, EXTREME TACTICAL, TACTICAL EXTREME SNIPER, Remchester .2991/2 (mod2.3v1) Super Dooper Extra Short Neck (SDESN) Express Magnum!!!!

Sheesh! Don't you guys get "Tactical Extreme Mall Ninja Monthly, The Magazine For Operators Who Have Been There and Done That!!!!"?

[Mk42gunner]

Geez Bret,

Now you're giving away the secrets of the WBXINBANCA, (WannaBe eXcept I Might Break A Nail Club of America).


Robert

[TAWILDCATT]

my son in cal was testing a rifle he wanted to buy.a rem 700 in 7 mm rem mag.
he went to gun store and they sold him a box of rem mag.first shot the stock blew.the cart was a 270.I asked did you notice the dif in case to rest of box,he said they all looked alike.I told him they sold him 7 mm rem mag ultra.then I called rem and blasted them for making near alike cart.especialy with all the new shooters.

[Multigunner]

First time I heard of a .308 being fired in a '06 chamber was when they used chamber inserts to convert some Navy M-1 Garands to 7.62NATO. The inserts were just held in by some sort of locktite and a wedge fit, sort of like the tie rod ends of a car.
They usually held up fine, but occasionally one would work loose and be ejected with a spent hull, then on the next shot the 7.62 was in the full length chamber.
Apparently nothing bad happened, just those funny looking empties.
They still sell these inserts occasionally, saw some adverted awhile back.

Hatcher's Notebook tells of two teenagers trying out an heirloom 7.7 Jap rifle with .35 Remington ammo, they had to beat the handle with a mallet to lock the action.
It held up for two rounds and on the third the action shattered and sent shards of steel into the shooter's brain, kind of suprising that he actually had one.
The kid survived after some delicate surgery.

You occasionally hear of a greatly oversized bullet being fired without the rifle blowing up, but claims that there was no excessive pressure sound like bull to me.
Recent reseach done by the British Proof house and Radway Green has proven that bullets even a few thousandths oversize can increase pressure into the danger zone. And I've read of custom Ruger No.1 single shots being built with a .303 chamber and a .308 bore to test the various .308 bullet shapes at .303 velocities. Those rifles were tested to determine if firing a standard .311 bullet in the .308 bore would cause any problems and results indicated an aprox 7-8% increase in pressures.

Bullet construction can be the deciding factor on just how high the pressures can go.

There have been tapered bore rifles built to take advantage of the squeeze bore effect once used for anti tank rifles. As the bullet is swaged down the dimishing size of the base somehow keeps the acceleration effect from leveling out.

One factor that may have allowed a oversize bullet to work as decribed is an oversized 6.5 bore coupled with a serverely eroded throat, or the leade wallowed out by the locator plug of the reamer.
It would not be easy to push the pilot of a 7mm or .30 reamer into an unaltered 6.5 bore.

[Mk42gunner]

There have been tapered bore rifles built to take advantage of the squeeze bore effect once used for anti tank rifles. As the bullet is swaged down the dimishing size of the base somehow keeps the acceleration effect from leveling out.

All I have read and the pictures that I have seen, have the tapered bore rifle projectiles having a skirt or flange, usually at the base and the turn of the ogive, that collapsed when the bore size decreased.


It would not be easy to push the pilot of a 7mm or .30 reamer into an unaltered 6.5 bore.

Just guessing here, but anyone that would do this probably ground the pilot off, without a thought. I can't imagine anyone doing this if they actually thought about it, and verified which Japanese rifle they had.

Robert

[Multigunner]

All I have read and the pictures that I have seen, have the tapered bore rifle projectiles having a skirt or flange, usually at the base and the turn of the ogive, that collapsed when the bore size decreased.

The Salvo Squeeze bore project took it further and used five short fat soft metal projectiles and swaged these down to a slimmer profile.
A .50 BMG was rigged to squeeze the projectiles down to .30 caliber giving five bullets pershot so at 600 rpm it delivered 3,000 Projectiles to the beaten zone per minute.
A 7.62 version used three 29 gr projectiles squeezed down to .15 caliber, velocity about 4,000 fps.

I'm pretty sure there were a few commercial sporting rifle prototypes that used standard lead core jacketed projectiles with a bit less reduction in caliber to acheive ultra high velocities.




Just guessing here, but anyone that would do this probably ground the pilot off, without a thought. I can't imagine anyone doing this if they actually thought about it, and verified which Japanese rifle they had.

Robert

Could be, but a roughly ground down pilot would probably wallow out the leade, most likely into a taper.

PS
An Arisaka collector and gunsmith I mentioned this to tells me he knew of 7.7 rifles being blown up by 7.92X57 rounds, something known to have happened to Springfield rifles when ammo got mixed.
The neck of a 7.92 if driven into a 7.7 chamber neck would probably result in a terrific pull strength and resistence to bullet movement., probably the same factor would be at work to a lesser degree in the longer .30/06 chamber.

Since a bullet, even an FMJ, can be swaged to a smaller diameter by a simple hammer blow the amount of pressure needed to swage the oversize bullet to the bore is only a small fraction of the total available energy of the charge.
If the initial pressure rize were slow enough the bullet would be pushed into the rifling before pressures built to the breaking point.
Something you might get away with several times using one propellant might result in catastrophic failure on the first shot if using a different propellant.

[swheeler]

my son in cal was testing a rifle he wanted to buy.a rem 700 in 7 mm rem mag.
he went to gun store and they sold him a box of rem mag.first shot the stock blew.the cart was a 270.I asked did you notice the dif in case to rest of box,he said they all looked alike.I told him they sold him 7 mm rem mag ultra.then I called rem and blasted them for making near alike cart.especialy with all the new shooters.

The 7mm RUM won't come close to chambering in the 7mm Rem mag, must have been something else.

[Multigunner]

The 7mm RUM won't come close to chambering in the 7mm Rem mag, must have been something else.

Could a 7mm Express, the old .280, if fired in a 7mm magnum chamber which would be greatly oversized in diameter as well as length, have blown back enough gas to give that result?

Seems to me I'd heard of a .280 rem being jammed into a .270 Winchester chamber with similar results.