We probably all know about some wrong ammo kaboom combinations. I usually shoot 3-4 rifles each range trip and am mindful of potentially disastrous mixing up ammo, such as the well known 223/300 Blackout no-no. For example, try a 308 in a Creedmoor and there's no way to close the bolt because of the longer headspace of that 308 round. But yesterday I heard of a kaboom from chambering a 308 round in a 270 Winchester rifle. Never heard of this one before so I measured these cases. The base of the shoulder of a 308 is only about .002" greater than a 270 case diameter at that point along its length. So yes, a 308 could "chamber" in a 270 and send a 308 bullet into a .277 bore.
Kaboom combinations
- Thread starter robert8904
- Start date
dellet
Gold $$ Contributor
There are a few 308 in 30-06 parent case chamber that will load and fire. 308 in a 25-06 is another.
Any time you have a cartridge with a shorter parent case and a larger diameter bullet, it’s possible. Just depends on if it’s short enough to headspace off the bullet instead of the shoulder.
Then there are some odd combinations you can find reference to. 6mm BR in a 223 WSSM. 7.62x39 in a .243 W.
Not all of these listed will blow up, but it’s interesting to research some of the combinations and find references to examples that did.
Any time you have a cartridge with a shorter parent case and a larger diameter bullet, it’s possible. Just depends on if it’s short enough to headspace off the bullet instead of the shoulder.
Then there are some odd combinations you can find reference to. 6mm BR in a 223 WSSM. 7.62x39 in a .243 W.
Not all of these listed will blow up, but it’s interesting to research some of the combinations and find references to examples that did.
Loudenboomer
Silver $$ Contributor
.308 in a .270. Disastrous. Happened to an old friend of mine many years ago. Much of the gas was directed down the magazine well. still blew the barreled action out of the stock. Bad wood splinters in left arm and small splinters to the face. No eye damage. A sharp guy and good hunter. In too big of a hurry.
Loudenboomer
Silver $$ Contributor
In P.O. Ackley book he tells about a guy who brought him a 30-06 built on a Jap Arisaka. Said it kicked like a son of a gun. O'l P.O. got to checking and the do it your selfer he got the rifle from chambered it to 30-06 alright but left the 6.5mm barrel on it! P.O. fired the rifle many times with factory loads. A I remember it he kept loading it hotter until he was able to blow the barrel out of the action. He was able to screw the barrel back on and fired the rifle again.
jelenko
Gold $$ Contributor
Wait. Are you saying a 308 bullet made it through a 6.5mm bore?
yep! seen several 308 bullet that have shot out of a 224 bore. the guns were blew into multiple pieces but the bullets made it out. And seen one that did not make it out.
never take a 300blk shooting if you also have a 556.
I almost had this happen to me. The old lady was loading mags at the range. Somehow a 300blk got into the mag. Luckily it jammed. Here is the thing, I don't own a 300 and I reload all of my ammo. I am thinking it was laying on the range table and I did not see it. If it would have blown up my gun I would have never thought this could happen. I would have blamed myself for something I did reloading the ammo.
never take a 300blk shooting if you also have a 556.
I almost had this happen to me. The old lady was loading mags at the range. Somehow a 300blk got into the mag. Luckily it jammed. Here is the thing, I don't own a 300 and I reload all of my ammo. I am thinking it was laying on the range table and I did not see it. If it would have blown up my gun I would have never thought this could happen. I would have blamed myself for something I did reloading the ammo.
Load your own shoot your own has worked for me for the last 45 years .
And I mean at the range or on the hunt
And I mean at the range or on the hunt
Loudenboomer
Silver $$ Contributor
Wait. Are you saying a 308 bullet made it through a 6.5mm bore?
Yes. A very good story in one of P.O.'s Books. Maybe someone with more skills could post a link to it.
Yes. A very good story in one of P.O.'s Books. Maybe someone with more skills could post a link to it.
I have seen a 7x57 through a 270. Twice. One shot wrecked a Colt Sauer. Three shots did nothing to a Savage 110. Saw a 303 British fired through a Parker-Hale 7mm Mag. Blew the extractor out, split the stock, blew out the magazine. The action and barrel were otherwise unhurt. I replaced the extractor and bottom metal and repaired the stock. It was fine. 303 Savage in a Lee Enfield worked out well enough. The owner was convinced the Savage cartridge was more effective on big game. WH
Adam in WI
Practically lives here
I've heard this as well. It was referenced in an old issue of American Rifleman. Evidently they were able to fire the rifle repeatedly, even recovering .30 cal slugs swaged down to 6.5mm
Adam in WI
Practically lives here
Arisaka Action
Below I have copied the text of the note from The American Rifleman story about the 6.5 rifle rechambered to .30-06. It's neither BS nor an urban legend. The gunsmith, Enique Mahnke, had an unusual name that can be checked with google. I'll try to include one of the photos that appeared...
First post in the thread. May 1959 issue of American Rifleman. Guy thought he was rechambering a 7.7 Arisaka, but it turned out to be a 6.5.
swd
Silver $$ Contributor
We had a client accidentally chamber a 308 in a 264 Win Mag and it headspaced close enough to fire. Blew out the follower and floor plate, cracked the stock, locked up the bolt in the action and set back lugs slightly. Amazingly it didn’t crack the barrel. We had chambered the 264WM barrel and the customer was mad as hell because he didn’t realize what he had done. He was m effing us and talking law suits until we took the barrel off and you could still read 308 WIN on the back of the case. He got real quiet real fast..
I may have recounted the case where a customer had me barrel two rifles, both Remington 700 Classics. One was a 308 Norma, the other was a 7mm STW. Sure enough, one of his clients (he was an outfitter) grabbed the wrong rifle, or the wrong ammo. Either way, he ended up shooting a bear with the STW, only he used a 308 Norma cartridge to do it. The 180 grain Swift A-Frame bullet swaged down OK and the bear was killed with one shot. Good thing, he wasn't going to get another! They broke the bolt handle off, beating on it. I was able to remove the barrel and get the bolt out. I replaced the bolt handle, resized the bolt nose (I made up a tool just for that purpose) and replaced the extractor. Headspace was fine and the rifle was back in service. WH
divingin
Gold $$ Contributor
The first pic is a 300BO (.308") that was fired in a 223 AR. Can't say it made it through - it was about a foot along the largely destroyed barrel. This guy was a range scrounge - picked up live rounds, took them home and popped them in a mag. When he got enough, he'd shoot them ; he didn't notice he had picked up a BO round along with the 223/5.56 and popped it into his mag. Rifle was largely destroyed; any salvageable parts were beaten to death by the owner, who considered them haunted or something.
Bottom line: You can swage bullets down in a barrel. Once.
The second pic is less destructive: The result of firing a 223 cartridge in a standard 7.62x39 AK. Done by a rifle instructor teaching his student how to [not] operate his AK.
Similar to the second (no pic) was a couple of guys with a 300 WinMag who bought 300WSM ammo. When it didn't chamber, they resorted to loading .30-06 and firing it. Didn't extract, but they figured that was better than getting the correct ammo. They weren't allowed to continue.
Attachments
nakneker
Gold $$ Contributor
It’s easy to make a mistake like 300 BO in your 5.56 AR. I think anybody taking on the hobby of reloading would do their self a favor by reading threads like this or better yet just seeing pics of the results when things like this happen. Pics leave more of an impression.
I use to laugh to myself when people made simple mistakes but after loading going on four decades now I’ve seen how easy it can be to let your guard down.
Best way I’ve found to avoid Kaboom combinations is to triple check your load data and your components when loading. Following basic rules like one powder out at a time. When you go shooting double check your gun and ammo. For example I have multiple Blackhawk hunters in 41 mag, 44 mag and 45 Colt, it would be easy to make a mistake.
I use to laugh to myself when people made simple mistakes but after loading going on four decades now I’ve seen how easy it can be to let your guard down.
Best way I’ve found to avoid Kaboom combinations is to triple check your load data and your components when loading. Following basic rules like one powder out at a time. When you go shooting double check your gun and ammo. For example I have multiple Blackhawk hunters in 41 mag, 44 mag and 45 Colt, it would be easy to make a mistake.
Although accidents happen and that's exactly why we have the word accident.... Taking the time to insure your shooting the correct ammo in the correct gun isn't exactly a long period of time and there's only one person on the planet that's responsible for it.... Other than the 5.56 / 300BO problem which I can see why it happens should be the only mistake that's easy to make and exactly why I don't own the 300BO because I do shoot the AR platform a lot...
Sorry to say but letting reloading mistakes such as having primers installed backwards etc should never get any further than your reloading bench.... Visual Inspection of things is just to easy to do , check EVERY round... As long as there's people doing dangerous things there will be accidents BUT most could easily be stopped by taking the time to simply look at what your doing before you start... Actually read what it says on the front of the powder bottle , don't just glance or look but read what it says can stop some serious problems from ever occuring... Clearly labeled ammo boxes are a must.... We all know to only have one container of powder on the bench... So why not only have the ammo you need for a gun out at one time since most people can only shoot one rifle at a time.... This is something I see constantly , five different types of ammo or even more stacked on a bench...
I spend a lot of time on a skeet or sporting clays station and you would think an over/under shotgun would be fairly safe gun... Unfortunately I heard a story the other day about a guy who switched from 20ga to 12ga and mistakenly left a 20ga round in his shell bag , he was in a hurry and not paying attention and dropped the 20ga shell in the chamber of a 12ga and then stuck a 12ga shell behind it... Seems possible but I have never tryed to duplicate it... When he pulled the trigger it blew the gun up... I almost always glance down the barrels to check for any obstruction before loading and it only takes a second literally... Unless you're in a shooting situation that's life or death take that second and look at things , don't have ammo out that your not using , all these accidents could be prevented with two seconds of looking at what's happening.... Complacency is our problem, all of us...SLOW DOWN FOLKS you are your safety expert , nobody else is responsible for your safety... All these stories should teach us how not to do things... As an ex Leo I can tell you alot of the training is from mistakes people have made and got killed and their teaching you not to make the same mistakes , this applies to everything in life...
Sorry to say but letting reloading mistakes such as having primers installed backwards etc should never get any further than your reloading bench.... Visual Inspection of things is just to easy to do , check EVERY round... As long as there's people doing dangerous things there will be accidents BUT most could easily be stopped by taking the time to simply look at what your doing before you start... Actually read what it says on the front of the powder bottle , don't just glance or look but read what it says can stop some serious problems from ever occuring... Clearly labeled ammo boxes are a must.... We all know to only have one container of powder on the bench... So why not only have the ammo you need for a gun out at one time since most people can only shoot one rifle at a time.... This is something I see constantly , five different types of ammo or even more stacked on a bench...
I spend a lot of time on a skeet or sporting clays station and you would think an over/under shotgun would be fairly safe gun... Unfortunately I heard a story the other day about a guy who switched from 20ga to 12ga and mistakenly left a 20ga round in his shell bag , he was in a hurry and not paying attention and dropped the 20ga shell in the chamber of a 12ga and then stuck a 12ga shell behind it... Seems possible but I have never tryed to duplicate it... When he pulled the trigger it blew the gun up... I almost always glance down the barrels to check for any obstruction before loading and it only takes a second literally... Unless you're in a shooting situation that's life or death take that second and look at things , don't have ammo out that your not using , all these accidents could be prevented with two seconds of looking at what's happening.... Complacency is our problem, all of us...SLOW DOWN FOLKS you are your safety expert , nobody else is responsible for your safety... All these stories should teach us how not to do things... As an ex Leo I can tell you alot of the training is from mistakes people have made and got killed and their teaching you not to make the same mistakes , this applies to everything in life...
Adam in WI
Practically lives here
That had to kick like hell
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