Have you ever wondered what would happen if...

[quigley257]

I have a yet explained near "catastrophic" overpressure situation that occurred around 1987 with a Remington 700 Heavy Barrel Varmint in .223 Rem…….that certainly ""was not" welding!

I was called, the day before the "EVENT by a friend suggesting that we go "Prairie Dogging" the next day. I cleaned my Remington for tomorrow's shooting.

As I had nothing loaded, I loaded up 50 rounds for the following day.

We arrived at a little "Prairie Poodle" village, where my friend and his wife took out a few. When it was my turn, with a squeeze of the trigger…..all Hell broke loose!

I received a pretty good jolt to the shoulder, remember this is a .223 Rem. fired in a heavy rifle! Smoke erupted from every opening in the action! When I attempted to open the bolt …..it wouldn't budge.

To say I was surprised and bewildered is an understatement.

I went home, pulled and weighed the remaining 49 cartridges and found nothing wrong.

I took the rifle to a 'smith that hammered (glad I didn't witness it) the bolt open. The extractor was destroyed…..but no other damage was found. The .223 Rem case was now a "belted " case.

After all of these years, my only explanation is……after cleaning the rifle, I leaned it in the corner of my basement reloading area and a bug/wasp/something built a nest in the barrel

I still see that as unlikely though…..it was less than 24 hrs. prior to shooting, and in SW Wyoming there just aren't a lot of insects that would plug a hole that quickly for a nest!

The floor is now open for comments! memtb

Perhaps a patch or other remnant of the previous nights cleaning . It would amaze some people just how very little liquid it takes(bore solvent, oil, or rain drops) to radically drive up pressures. Just a guess...

 

[fruitnut]

I can see a cup and core 308 swagging down to 284. Especially something soft like a Berger. I think you could do that with the right die by hand. 308 to 224 is another story.

And a solid copper bullet would also be another matter IMO.

In the original incident, A max powder charge in a 300 WM is less than a starting load in 7 RUM. So that helped limit pressure.

In another incident I read about lately, A guy blew up his rifle with 57 grains of Varget behind a 140 gr in 6.5 PRC. I'm not sure how much of an overload that is. But to me that's a more scarry proposition.

 

[memtb]

What was the load? Do you remember?

Just curious, I had a similar experience in the mid 70's. Before Hodgen started with their extreme powders. Had the ammo laying in the sun. Almost burned my fingers when I grabbed it to load it in the gun. Safe load at 70° not so safe at 100° +.

I can look back in my records, but I'm pretty sure it was 22 or 23 grains (just above listed max) of IMR4198 and a 55 grain SP bullet (unsure of manufacturer), using a standard primer which probably was a CCI.

Addendum: Man…..what a memory! I didn't trust myself. I was spot on ……and the load was 23.0 grains! I amaze myself at times! memtb

 

[memtb]

Perhaps a patch or other remnant of the previous nights cleaning . It would amaze some people just how very little liquid it takes(bore solvent, oil, or rain drops) to radically drive up pressures. Just a guess...

Liquids…..possibly. Patch …no, as I always used the "eye" type rod! memtb

 

[Frog4aday]

Under no condition would I believe that or since the action I'd not solid it would release some of the pressure but I'd need to be there to believe a. 308 could travel in a .224 bore without causing extreme problems...

I'm with you - seems highly unlikely a .308 cal bullet could swage down to .224 size in a barrel but since the .300 AAC Blackout came along and gained popularity in the AR platform, a few have found their way into .223 Rem/5.56 chambered guns and shtuff happens!
This link has pics and descriptions:

LFD Research Films the Firing of .300 Blackout in a .223/5.56 Chamber

LFD Research simulated a catastrophic failure by chambering a .300 Blackout round into 5.56 AR-15 and filming it in slow motion.

www.thefirearmblog.com

Here is the ".308 dia bullet swaged to .22 cal":

 

[Frog4aday]

@Frank in the Laurels
Here is the thread. I knew it was somewhere on this site!

His AR15 blew up

Thanks for your reply! A man’s intelligence can be measured by how much he agrees with your opinion! LOL 😂 Albert Einstein or Mark Twain? Cheers

www.longrangehunting.com

Here is how a .300 AAC round can "headspace" in a .223/5.56 chamber and be fired:

 

[Calvin45]

I've long been intrigued by the .350 rem mag cartridge. But it's very sobering to think how many standard length and full length belted magnum chamberings that little troublemaker would chamber just perfectly in….