Colt Expanse Kaboom

[rickgman]

Another issue was what Bullseye and PPC competitors were reporting with reduced charge weight loads in .38 Special. The revolvers used in competition were durable enough that competitors did not see damage when they noticed increased recoil and a dramatic increase in muzzle blast.

I experienced this phenomena while developing gallery loads for a 30-06 using Bullseye gunpowder.

I have seen photos of .38 SPL revolvers with the cylinder literally blown apart from what reportedly was a detonation of a very light Bullseye propellant charge. I think the first time I read about this phenomenon was in the old NRA Firearms Fact Book. The transition from a deflagration to a detonation is very unpredictable and difficult to initiate even when using gaseous fuels or atomized liquid fuels. It is exponentially more difficult to initiate when using a particulate solid fuel (like small arms propellant). The conditions have to be just right for detonation of small arms propellant to occur. That doesn't mean that it can't happen but it is very unlikely to occur under all but the most favorable conditions. Use of slow burning propellant (like rifle propellant) makes it extremely unlikely. Add to that a small volume case and it is virtually unheard of.

As for using a small amount of Bullseye propellant in a large volume case (like a .30-06 case). That's something that I would discourage.

[lysander]

You are probably looking in the wrong places...

In the artillery and tank gun world, the existence of pressure waves caused by large chamber ullage, rapid burning propellants and ignition characteristics is a known and studied phenomenon. Pressure waves with delta P magnitudes of 80,000 psi have been measured.

[Butch]

You are probably looking in the wrong places...

In the artillery and tank gun world, the existence of pressure waves caused by large chamber ullage, rapid burning propellants and ignition characteristics is a known and studied phenomenon. Pressure waves with delta P magnitudes of 80,000 psi have been measured.

Dr. Courtney?

[Moose-Knuckle]

I've never seen that branding on a Federal box.

Guess this is their latest graphics?

Forgive me if I missed it but has the lot number or any further information about the particular Federal 5.56 been posted?

[ST911]

I've never seen that branding on a Federal box.

New-ish packaging, available in several major sporting goods retailers.

[PolishMike]

Finally got validated! Only took 5 years. I'll go through and answer questions.


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[MSW]

Any more info on the cause of failure? I'm looking to understand & (hopefully) avoid such an event.

[Hammered_Pair]

I know this is an older thread but the bolt supplied with the CE1000 is 9310 steel not 158 Carpenter, not sure if that had anything to do with this but it may be worth investigating.

[hk_shootr]

Any more info on the cause of failure? I'm looking to understand & (hopefully) avoid such an event.

+1 please

[MegademiC]

Finally got validated! Only took 5 years. I'll go through and answer questions.


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Now this is funny.

Regarding detonation, I know with guncotton, packing it tight results in a mild explosion while looser packing will increase intensity (and perhaps brissance). This is due, based on what I read, to the heat and shock being reflected off the shell (but not enough to rupture it) back into the fuel, speeding up the combustion.

As mention, slow burning powders, a small vilume, and a less rigid case would reduce risk. I think you may see it with 40 reloads on occasion, but that's based off reports, not experience so I could be off with that.

Curious on update as well.