Documented case of SEP?

[katastrof0]

Hi there!

Does anyone know of a documented case of a SEP Secondary Explosion Effect? Everyone keeps talking about them but darn if they can come up with something to back up the claim. Do they happen? Or is it a myth?

I wish i had a piece of crap revolver that i really didnt care to much about. Then start with a listed minimum load and load down in .2gr increments untill a SEP or a stuck bullet occured and document the whole event with pictures and pressure data. That would make a interesting post wouldnt it?

BB John

 

[rcmodel]

IMO: There is no such thing as "Detonation" or SEP in small arms ammunition with reduced loads.

Cowboy Action Shooters blow up a lot of SSA clones due to reducing the loads to the point bullets stick in the barrel.
Or they crank out Sundays loads on Saturday night, on a 2 grand Dillon, while drinking beer, arguing with the wife, and watching the NFL game on TV at the same time.

That results in double charges of fast pistol powder.
BOOM!

Reduced load Magnum rifle blow-ups are caused not by powder "detonation", but by a bore obstruction.

The primer fires, the reduced load fails to build pressure fast enough, the bullet moves into the rifling, and sticks / stops.

Then the rest of the charge lights off and the bullet can't overcome the static friction and get going fast enough again to unplug the bore!
Boom!

No reputable ballastics lab or powder manufacture has so far been able to creat a smokeless powder "detonation" in anywhere close to the size of a rifle or pistol load.

Even 1 & 8 pound cans of smokeless powder cannot "detonate", even if you put a fuse & blasting cap in the can. All it will do is burn normally, as the hypersonic detonation wave from the blasting cap cannot pregress through the small amount of powder in the can.

Because there is not enough mass in the charge to sustain a detonation wave through it.

Smokeless powder can certainly "detonate".
But only when there is mass quanities of it, like in a warehouse, or railroad car full.

It is simply impossible in small quanities as would be found in reduced loads of rifle or pistol powder.

rcmodel

 

[Shoney]

My understandings of SEE came from an article in American Rifleman well over 20 years ago, maybe longer.

The phenomenon is theorized to occur in reduce rifle loads that are well below the minimum load. The greater the reduction, the greater the chance of catastrophic problems. Going a good deal below minimum load has always been promoted as a dangerous and unwise practice.

As I recall it made the point that SEE (Secondary Explosive Effect) is more commonly referred to as detonation, but that in reality it was not a detonation, rather a unique pattern of burning of the powder.

The article theorized that the small amount of powder can lay flat in the horizontal case. Primer ignition hits the rear portion of the powder, igniting it but skips over the middle section of powder, ignites the front portion of the powder, and both burn rapidly toward the middle. The result is theorized to be an uneven but rapid burning of the powder, causing a very high pressure spike.