What would happen if you touched off a .308 in a .30-06 chamber?
- Thread starter philthygeezer
- Start date
- Location
- The Conservative part of Ontario
That sort of fire forming might be reasonably safe with a fairly new case, but I think a reloader that has a bunch of much used brass might get a face full of hot gas.
I did a stupid thing some time ago, with 308, in that I used a shell holder that had been filed down. About one in ten refused to fire, and some refused to extract.
this in a BLR, basically, a push feed. The extractor pushed the case too deep, never snapping over the rim.
Those that did fire, exhibited no issues, other than fire forming back to size.
Edit
this thread got me thinking.
On rechecking that brass, I found that it had stretched in the case web area, to the point that it could result in a case head sep.
I pitched all that brass.
I did a stupid thing some time ago, with 308, in that I used a shell holder that had been filed down. About one in ten refused to fire, and some refused to extract.
this in a BLR, basically, a push feed. The extractor pushed the case too deep, never snapping over the rim.
Those that did fire, exhibited no issues, other than fire forming back to size.
Edit
this thread got me thinking.
On rechecking that brass, I found that it had stretched in the case web area, to the point that it could result in a case head sep.
I pitched all that brass.
Last edited:
I know of a gentleman out west who unsuccessfully fired an 8mm Mauser out of his Garand rifle, chambered for 30-06... Lucky for him he walk away with now healed wounds. The Garand didn't fair as well. This quite likely happened in World War I with 1903's as well...
A 308 fired in a K31 (7.5X55) fireforms to the chamber and the projectile fires normally (and quite accurately). No shrapnel, no smoking crater, no fuss.
Not a good idea, but further proof that guns are not as dangerous as many fear.
Not a good idea, but further proof that guns are not as dangerous as many fear.
This is an honest to God true story. It happened in my community about 10 years ago and was related to me by the then owner of our sporting goods store. A fellow came into the gun store and complained that he had been sold defective ammunition and wanted his money back and his gun checked over for free in case it had been damaged. He had just bought the gun, and scope recently from this store after passing his CORE. He had fired two rounds in his new rifle and they came out blown out straight walled He said the gun jumped all over the place and he couldn't hit anything. The gun was intact. The owner asked to see the ammo and it was .308 calibre. He said to the customer, "You picked this ammo out. It says right on it .308 but your rifle is a .30-06. Can't you read?"
In response the customer said, "Yes I can read but the print is really small and I am legally blind!"
So, to answer your question, yes, you can do it.
Addendum: The fellow who passed him on his CORE course was known for passing anyone and everyone who took his course. He was charged a year or two later and was convicted. He doesn't do CORE anymore.
In response the customer said, "Yes I can read but the print is really small and I am legally blind!"
So, to answer your question, yes, you can do it.
Addendum: The fellow who passed him on his CORE course was known for passing anyone and everyone who took his course. He was charged a year or two later and was convicted. He doesn't do CORE anymore.
However, I just faked a test with an aluminum .308 snap cap in a .30--06 Encore, and the firing pin drove the case forward into the chamber. I had to give it a tap with a cleaning rod from the muzzle end. No grooves or anything on the end of the snap cap: just a very light mark or two.
I'll bet the rearward force of expanding gas holds the case against the bolt.
I realize that there is an inherent danger factor anytime you try to use the wrong ammo in any rifle, however, I must unfortunately disagree in this instance.
The .308 is a cut down .30-06. Therefore the case is basically the same size all the way to the .308 shoulder. The length of the brass case is long enough to actually reach the .30-06 shoulder. How does this make it practically impossible to chamber? Did you think about that statement?
(You can also theoretically chamber and fire a .270Win in a .30-06, if the chamber were military or just sloppy. The shoulder length is only about .010" greater than the .30-06. The O/S dimensions of the neck is about .308". That allows the extra length of the neck to fit into the chamber, centreing the case the while the bullet is pointed into the rifling. Since the bullet is wa-a-a-ay smaller than the barrel, no pressure issues, I would imagine that accuracy would suck though.)
Back to topic...That is why the .308 fire-formed brass has a slight shoulder at the mouth. Pull the trigger, if the extractor holds the base against the bolt face, then the primer will be struck. The case is centred in the chamber, powder ignites, pressure builds, forces the brass outward to conform to the chamber. bullet starts downrange. Gas won't escape from the chamber unless it is filled. So, once the brass fills the chamber and even makes a shoulder the brass should be pushed back against the bolt face, obturation must, and will, occur. Escaping gases are contained, and gas will be fully directed downrange. No harm, no foul. Worst case with new brass, overworked shoulders. Although I haven't seen case separations, I wouldn't rule them out but with new, never fired brass. Case separations occur when head spacing is too long. And in this case, since the cartridge headspaces on the shoulder, it is REALLY short.
Personal case:
Many years ago, I bought a used rifle. Gewehr Mauser K98, re-tooled after the war. On it was/is stamped 7.62mm. That was it. Guy who sold it to me also gave me some .308 rounds to check it out. I fired all 5 of them, not checking simply working the action, and each fed, fired, and extracted well. When I was done, I picked up my brass, like I am supposed to. I had already bought .308 dies and when I looked at the brass, I knew something was wrong. I had 5 straight walled cases with just a slight shoulder at the mouth.
I took it back to my buddy. He immediately knew that it was chambered to .30-06. He had simply taken the rifle on trade a few weeks before and thought it was a .308, since that is how it is marked. The owner didn't know either, it had been his grandfather's. He wanted a newer looking rifle. I have since used it as a .30-06 for about 12 years now and it works great.
I would not have done this intentionally, but the rifle proved safe and there were no ill effects. Each round went down range.
bearkilr
CGN Ultra frequent flyer
- Location
- Nowhere, ......just past the middle
You're still firing the same diameter bullets in all instances, so less damage usually occurs.
You start running into serious problems when you try to squeeze a bigger bullet through a smaller bore.
I've fired 270 out of a 30/06 at a wounded bear(don't ask,long story), and nothing happens, except a more muffled bang and no accuracy. Now all my guns have the buttstock shell holders.
On the flipside, I've seen a Mauser chambered in 7x57 that had fired a 30-30 round. The shooter survived with minor injuries, but it destroyed the bolt,scope,stock,etc. A lucky fellow !!!
You start running into serious problems when you try to squeeze a bigger bullet through a smaller bore.
I've fired 270 out of a 30/06 at a wounded bear(don't ask,long story), and nothing happens, except a more muffled bang and no accuracy. Now all my guns have the buttstock shell holders.
On the flipside, I've seen a Mauser chambered in 7x57 that had fired a 30-30 round. The shooter survived with minor injuries, but it destroyed the bolt,scope,stock,etc. A lucky fellow !!!
longbranch*
CGN frequent flyer
- Location
- Victoria,BC.
.308 in '06
Did that once by mistake, many years ago. Had several different calibre rifles at the ranch. Fired a .308 through my .30-06 7600 carbine, shot felt normal, even hit the bullseye! Still have that straightened out case in my gunroom just to remind me.
Geoff
Did that once by mistake, many years ago. Had several different calibre rifles at the ranch. Fired a .308 through my .30-06 7600 carbine, shot felt normal, even hit the bullseye! Still have that straightened out case in my gunroom just to remind me.
Geoff
OK, I had thought the 308 case was short enough that it would not seal the chamber and gas would escape. However, it appears long enough to seal the chamber.
Rookie Wildcat, you said, "The .308 is a cut down .30-06. Therefore the case is basically the same size all the way to the .308 shoulder. The length of the brass case is long enough to actually reach the .30-06 shoulder. How does this make it practically impossible to chamber? Did you think about that statement?"
The 308 is quite a bit different than a cut down 30-06. It must be a very sloppy chamber in a 30-06, to easily accept a 308 round.
A 30-06 case is .4698" above the rim, while a 308 is .4703". That's .005" right at the solid part of the case, so the 30-06 chamber would have to be that much too large, for the 308 case to go in.
However, at the shoulder, the 308 case is .013" larger and that is a considerable amount in a rifle chamber, .441" against .454" for the 308.
I can see a military 30-06 having a large enough chamber to accept a 308. However, I have just measured empty 30-06 cases fired in a Husqvarna and a BSA. The average size at the shoulder is .444 of the empties from those two commercial rifles. Thus, it would take considerable power, certaily abnormal power, to force a 308 cartridge into either of those two rifles of mine.
Rookie Wildcat, you said, "The .308 is a cut down .30-06. Therefore the case is basically the same size all the way to the .308 shoulder. The length of the brass case is long enough to actually reach the .30-06 shoulder. How does this make it practically impossible to chamber? Did you think about that statement?"
The 308 is quite a bit different than a cut down 30-06. It must be a very sloppy chamber in a 30-06, to easily accept a 308 round.
A 30-06 case is .4698" above the rim, while a 308 is .4703". That's .005" right at the solid part of the case, so the 30-06 chamber would have to be that much too large, for the 308 case to go in.
However, at the shoulder, the 308 case is .013" larger and that is a considerable amount in a rifle chamber, .441" against .454" for the 308.
I can see a military 30-06 having a large enough chamber to accept a 308. However, I have just measured empty 30-06 cases fired in a Husqvarna and a BSA. The average size at the shoulder is .444 of the empties from those two commercial rifles. Thus, it would take considerable power, certaily abnormal power, to force a 308 cartridge into either of those two rifles of mine.
BC Bigbore
CGN frequent flyer
- Location
- BC's Peace Country
An aquaintance of mine did exactly that at the range next to me. He put away his Husquavarna .308 and took out his Savage 110 .30-06, accidently chambered a .308 cartridge and let fly At the shot, what felt like sand blasted my right cheek from the bench next to me and buddy had a stunned look on his face. It took a few minutes before we could get the bolt open and a funky, blackened case stamped .308 Win was removed from the .30-06 chamber. The primer was blown and the case mouth fire formed part way up the shoulder of the chamber. I don't know if he ever fired that .30-06 after that episode.
At the shot, what felt like sand blasted my right cheek from the bench next to me and buddy had a stunned look on his face. It took a few minutes before we could get the bolt open and a funky, blackened case stamped .308 Win was removed from the .30-06 chamber. The primer was blown and the case mouth fire formed part way up the shoulder of the chamber. I don't know if he ever fired that .30-06 after that episode.Any chance you could mic that case and a fl sized 308, and see if the snap cap is up to SAAMI spec measurements?My guess is that it is a touch small to ensure easy chambering and removal from any rifle.
I saw the results of a 308 fired in a 270 and it wasn't good. The rifle was a Remington 710 and the bolt locked into the barrel. It stayed together by welding the bolt lugs to the barrel. Any other gun would have blown up like a grenade.
