Reloading 223 very lucky escape

[Dalua]

It's not an increase in chamber pressure. It's the fact that any round which doesn't obiturate will be forced back hard onto the bolt face so the bolt will take much more pressure than a round that has obiturated properly as the case is then forced to grab the chamber walls. Think along the lines of a steel rod forced down the muzzle and then hammered with a sledge-hammer and you get the idea.

Thanks. So if there's no increase in pressure in this scenario, is it likely to have resulted in the primer's being squished to the extent we see in post 12?

 

[ChesterP]

That's the mystery which no-one knows the answer to as yet.

 

[Edinburgh Rifles]

primer flow and seized bolt -

not headspace or obturation or OAL or grease in chamber or oil in barrel could cause such elevated pressures

Massively increased burn rate in powder - either through wrong powder or powder break down (powders that are subject to storage or transport can often break down in the case resulting in smaller particles and drastically increased burn rate)

Barrel blockage - squib round or something similar


I just cant see how a bullet change and less than stiff charge of N133 would do this alone without a major physical change

 

[bullet chucker]

What result if any was taken to the flight of the bullet may it hit high with all the pressure behind it,Did it hit the target? Miss all together? Tumble maybe? Just a different point of view to a worrying scenario. Hope a solution to all the opinions given will solve this one.

BC.

 

[finnbear270]

What primers are in use?, AH, I see you posted Federals, do you have any Magnum primers on stock?

 

[Andy RV]

What did you use to clean the barrel? Patches?

 

[wraith]

Rather than an over charge, could this have been an undercharged load where it has spontaneously combusted causing a massive spike in pressure. If is quite easy to dump in a light charge if you are not paying attention. Then rather than burning in a controlled manner, the whole powder charge goes off at once raising pressures massively.

Significantly overcharging a rifle cartridge with a rifle powder is difficult as most loads pretty much fill up the case.

ust what i was thinking bud
j

 

[Muir]

ust what i was thinking bud
j

This is something that people like to be afraid of when reloading but in practice, it is almost impossible to achieve. (with most powders) The H.P. White Ballistic Laboratory (think SAAMI) had to work to make this happen under laboiratory conditions. They finally did get it to happen but had difficulty repeating it. I have personally seen a desired 23 grain charge of H335 mistakenly metered at 11 grains. The shooter fired 20 - 30 rounds before deciding to call it quits. All he got was heavily sooted cases.

FWIW, an oiled case will increase chamber pressure. The result is back thrust. When i was in gunsmithing school they were just finally condemning the practice of gunsmiths 'proofing' their work with an oiled factory cartridge.

As to the OP problem. If it's not overcharge, it was probably impingement of some sort, be it case neck or foreign matter. It is almost impossible to reverse engineer. I would have liked to see the case remnants. BTW, the steel, media in the case will cause this. I have seen it several times.~Muir