doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com CAUTION: Graphic Blow Up Injury

Mike,

It might not be as hard to do as you think....

True story: I was at our local gun range this past Saturday shooting skeet. A new fellow to the range was there with a brand new Ruger Red Label in 12 ga. that his wife and a friend bought him as a recent retirement gift. He was shooting reloaded ammo put together by another friend with a press, as he didn't have one as yet. His loads sounded appreciably louder than those of the rest of the squad and were noticeably punching him pretty good which took some doing as he was about 6' 4" and approaching 300 lbs. ....IOW...a big boy!

He just shot the one box, on our recommendation, and I asked if he'd give me a couple of those loads for dissection, as I suspected an overload. He kindly did, we exchanged phone numbers, and I called him that same afternoon to tell him the following:

The 1-1/8 oz. loads (in Federal Top Gun case) contained a loosely fitting Win. WAA 12 wad and 25.1 grains of 700X powder. Lyman loading manual called for just 17.0 gr. of the stuff for 1175 fps and approx. 9400psi. for a 47% overload in his case....or very near one-half again the amount of powder than what was required. It all fit in the hull quite nicely with an average looking crimp.....so it can be done! He was pretty stunned to hear this and vowed he'd cut open the few remaining loads he had to salvage the components. I can only hope he did....


rob

Robt. That give you an ideal of how stout the new Red Label is. Same load in most doubles would have been much more of a problem.

The theory of how you could get an overcharge of powder in a progressive loader goes like this, 1st powder charge drops but gets hung up in the tube, second charge drops and clears 1st and second charge drop into shell. When loading light loads the wad often has a short shot cup and a long cushion area. It is part of the theory that this cushion area collapses and makes room for the over load of powder.

You can never know for sure about these things after the fact. But I know 2 long time reloaders using progressive loaders that blow up chambers. Both dissected other shells from the session and found light or missing charges. One loaded up a double charge to test the theory. it pressure tested over 30,000psi.

Thank you Mark, and interesting. The shooter did comment that he has had an occasional light load/blooper.

Drew,
Is there any possibility that a 20G shell was accidentally inserted ahead of the 12G shell? Burrard illustrates similar "blow out" failures on guns with steel barrels, in his book the, Modern Shot Gun,Vol;3

I agree with the metal fatigue, and also commend the sharp set of eyes that noted the imprint of the Damascus pattern onto the exterior of the green plastic shell casing- I also concur with the oxidation pattern analysis presented- very true, more so with the amalgam of iron and mild steel used to make such tubes- it must also be remembered that the iron "skelp" admixture could consist of melted down horseshoes, nails, etc-- I am not a metallurgist, but when we worked for Townsend & Bottom on the West Olive (MI) plant years ago, for all those welders, myself included, who passed their coupon testing the first time, the company gave us a paid membership in the AWS- and I read and kept all my issues, and there is where I became interested in metallurgy, mainly ferrous such as we looking at here. How did the top and bottom ribs fare from this incident?? RWTF

The brown along the break indicates previous weakening from corrosion. Been there for awhile. Previous firing with corrosive primers gets into seams on the twists, doesn't get cleaned out with bore cleaner.

jawjadawg,

"Buchsemann, can you explain how these fatigue fractures would have occurred? Would one possible cause be the use of high pressure loads? The barrels might not have failed catastrophically at the time of use, but instead formed tiny cracks which then accepted moisture, leading to rust?

Do we all need to get out the microscope to take a closer look at our barrels?"

Rather than writing a lengthy description of how fatigue fractures come about I'll keep it short by saying such is caused by cyclic/repeated stressing and relaxing or loading and unloading of a material. The failure begins with a microscopic crack and over time the crack continues to propagate until the material finally lets go. The "beech marks" that I noted are trace evidence of this process having taken place though I personally haven�t viewed such in Damascus steel. I too noticed the impressions in the plastic hull which reminded me of an oops experience I had working up a regulation load for one of my double rifles. In short I zigged when I should have zagged with my powder charge and almost destroyed a rather expensive weapon and did bodily harm to my person. In addition to temporarily freezing my highly re-enforced action, stretching the material of the receiver to its upper limits (the gun had to cool a little before the cross-bolt released), the machining marks in the chamber where imprinted about the exterior of my brass case.

Again, I am no expert but it looks to me as if the exploded gun pictured in this thread has seen more than one heavier than necessary charge.

I like Damascus barrels and see "quality" tubes as being just as good as nitro barrels and far prettier when loaded correctly. IMHO the series "Finding Out for Myself" written by Sherman Bell is a must read for any early shotgun enthusiast; thinking a good idea for any "gunny" really.

Mark

PS - If you are concerned about the state of your barrels with regard to fatigue there are many materials labs scattered about the country, manned by "experts�, that could do some simple penetrant tests and other visual inspections for you to put your mind at ease. PM me if you want to go that route.

If those barrels had been stub twist, I would say those circular ribbons might have been from the barrel, but what would cause the hull to expand that much.
Certainly an overcharge of powder or wrong primer would not do that. It is as if the hull expanded by having something not letting if open.

Not even likely since the fracture doesn't follow either the weld joints of the ribbands, or of the Damascus pattern. I'll say this was due to high pressure. The problem is to determine what caused a pressure spike that ruptured the barrel. As for the rust, bare clean metal can have this amount of rusting overnight under humid conditions. We need to know how soon the picture was taken after the burst before we even consider that rust staining as significant. And how many guys at the gun club ran their fingers with salty perspiration across the fresh break? It would be nice to see if the primer of the ruptured shell is any different in appearance than others from the same box.