possible bad brass

[Cameron SS]

I believe the term is called "detonation"... way too little slow burning powder....

Jerry

I have been doing a bunch more reading on the subject of detonation, also sometimes referred to as Secondary Explosion Effect (SEE), and boy what a read.

Long story short, its a villainous unicorn. Lots of people claiming to have seen it, many denying its existence, many trying to find it or recreate it without success.

The majority of malfunctions ascribed to SEE are by amateur reloaders, which the experts quickly dismiss as user error, typically a double charge.

Virtually every powder manufacture claims its not a thing, but most will still issue warnings not to use reduce loads with slow burning powder.

I have searched 6 internet forums and couldn't find an authoritative source explaining what it is or even summarizing the more popular theories.

Even Hatcher himself didn't really spill much ink on the subject.

I suspect that in order for detonation/SEE to occur, several factors, at present not understood, must come together to produce the result.

Strict laboratory testing might be so controlled as to inadvertently not allow the variables to come together.

After a review of Hatcher's summary of common ammunition malfunctions, I would put my money on soft/annealed brass.

 

[ipscgraz]

Was the barrel clear when he fired these?

As mentioned, bullet diameter is correct?

 

[Alpheus]

What was the rifle? Maybe the bolt wasn't fully closed/out of battery?

 

[yomomma]

I blame Trump...

 

[Mystic Precision]

I have been doing a bunch more reading on the subject of detonation, also sometimes referred to as Secondary Explosion Effect (SEE), and boy what a read.

Long story short, its a villainous unicorn. Lots of people claiming to have seen it, many denying its existence, many trying to find it or recreate it without success.

The majority of malfunctions ascribed to SEE are by amateur reloaders, which the experts quickly dismiss as user error, typically a double charge.

Virtually every powder manufacture claims its not a thing, but most will still issue warnings not to use reduce loads with slow burning powder.

I have searched 6 internet forums and couldn't find an authoritative source explaining what it is or even summarizing the more popular theories.

Even Hatcher himself didn't really spill much ink on the subject.

I suspect that in order for detonation/SEE to occur, several factors, at present not understood, must come together to produce the result.

Strict laboratory testing might be so controlled as to inadvertently not allow the variables to come together.

After a review of Hatcher's summary of common ammunition malfunctions, I would put my money on soft/annealed brass.

Yep, the enigma wrapped in a mystery with a sprinkle of pixie dust.... but it has been reported off and on. I came about it in mainstream shooting mags long before a website was a "thing".

It was reported in magnum handguns running very light charges... apparently, guns did go boom. Then I saw it again in rifles but no one was able to repeat the destruction on demand.

So, it does take some weird series of events to coincide but it has been reported enough to not be discounted. The majors see it as a risk enough to put warnings even though they don't come out with a blanket endorsement.

SEE is a thing... looking for it is not a pastime I care for so I will put it up there with under inflated tires and eating food left on the counter for 3 days.

Why take the chance....

Jerry

 

[tiriaq]

The reported load, 35gr of 4831SC wi8th a 160gr bullet isn't a reduced load; it is a starting load, 35-40gr being a suggested range. 6.5x54MS is not a large case.
Out of curiosity, I'm going to weigh out some powder, and see what the load looks like in the cartridge case. That long 160gr bullet is going to use up some of the space inside the case.
I have a 6.5MS, built up on a Greek military action, and have rebarrelled a few 6.5MS rifles, so I have some familiarity with the rifle.
Based on experience with a couple of original 6.5 MS sporting rifles, tolerances like headspace can be rather approximate.

 

[Cameron SS]

Yep, the enigma wrapped in a mystery with a sprinkle of pixie dust.... but it has been reported off and on. I came about it in mainstream shooting mags long before a website was a "thing".

It was reported in magnum handguns running very light charges... apparently, guns did go boom. Then I saw it again in rifles but no one was able to repeat the destruction on demand.

So, it does take some weird series of events to coincide but it has been reported enough to not be discounted. The majors see it as a risk enough to put warnings even though they don't come out with a blanket endorsement.

SEE is a thing... looking for it is not a pastime I care for so I will put it up there with under inflated tires and eating food left on the counter for 3 days.

Why take the chance....

Jerry

In all my time at the lab, we never found a commercial benefit to the company for unlocking the mysteries of SEE. Especially because we had never encountered one ourselves, I couldn't even claim it was a legit health and safety issue. While curious, I had no illusions about my ability to succeed and discover something where so many other smarter, more experienced and better resourced ammunition experts had failed. I did commit a lot of time to reading about it though.

I found one research report from another ballistic testing house, HP White, that tried to recreate the effects of a gun kaboom where SEE was alleged to be responsible for the destruction of a magnum caliber revolver. In order to produce a damaged firearm and case consistent with the one that was claimed to be caused by SEE, they had to put a double powder charge AND TWO BULLETS into a single case.

The coolest testing we ever got to do, asides from shooting at different media, was V50 testing, where instead of trying to see if a particular material can withstand a .30 cal AP round at 800 m/s, we fire a series of shots to determine what velocity would be required to penetrate the material. Particularly resilient materials were the most fun because it usually involved firing these rounds a hair under light speed. Our record for fastest .30 cal 162 gr AP M2 round was a touch over 4700 fps, but this required flagrant disregard for what most people would call prudence, and a 36" long, 3" dia progressively rifled proof testing barrel chambered in .300 RUM.

 

[Cameron SS]

Double Tap

 

[pmatuk]

called back went to IMR 4350 36 g fed 210 primer woodleig 160 bullet
he tested 5 rounds no issue cases look good and easy opening rifle groups
Conclusion is "detonation"... the sc is no good for his MS
he now owns his second can of powder LOL.He just started to load ammo and will now do more research
As for chopping the rifle action he won't
Cheers All done

 

[444shooter]

called back went to IMR 4350 36 g fed 210 primer woodleig 160 bullet
he tested 5 rounds no issue cases look good and easy opening rifle groups
Conclusion is "detonation"... the sc is no good for his MS
he now owns his second can of powder LOL.He just started to load ammo and will now do more research
As for chopping the rifle action he won't
Cheers All done

Glad to hear all sorted out. The MS is best with the medium burning powders.

 

[Cameron SS]

called back went to IMR 4350 36 g fed 210 primer woodleig 160 bullet
he tested 5 rounds no issue cases look good and easy opening rifle groups
Conclusion is "detonation"... the sc is no good for his MS
he now owns his second can of powder LOL.He just started to load ammo and will now do more research
As for chopping the rifle action he won't
Cheers All done

Curious as to what evidence/factors lead him to that conclusion?

 

[Mystic Precision]

The reported load, 35gr of 4831SC wi8th a 160gr bullet isn't a reduced load; it is a starting load, 35-40gr being a suggested range. 6.5x54MS is not a large case.
Out of curiosity, I'm going to weigh out some powder, and see what the load looks like in the cartridge case. That long 160gr bullet is going to use up some of the space inside the case.
I have a 6.5MS, built up on a Greek military action, and have rebarrelled a few 6.5MS rifles, so I have some familiarity with the rifle.
Based on experience with a couple of original 6.5 MS sporting rifles, tolerances like headspace can be rather approximate.

In my Hrn manual, they list H4831.... NOT H4831SC.. quite a bit of load density difference in the two types of powder.

Glad there was a solution found but watch out for low density charges with slow powder.... use what is in print and do not go below their min charges.

When hunting, you don't always shoot level or up...

Jerry