doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Perazzi blow up

I have seen exactly one gun let go with factory loads. It was a K-80. The owner never reloaded and was extremely good about keeping his almost new gun in factory original shape. Much debate and hand wringing at the time never concluded the real cause. But he did get a new barrel and for end stock put on the gun by the maker. Not that they assumed any fault. Just to make him happy.

Most gun failures, when it is not the guns fault for being rusted out or pitted to a weak point, are the reloaders fault. If your gun is weak any shell could cause a failure. Most guns are in solid shape and take that extra measure of pressure or extra measure of dumb to make them fail. Get a base wad stuck in the barrel and they might fail. Use the wrong powder and they might fail. Use the wrong bushing and they might fail. Almost all gun failures are induced by the shooter by his error in my opinion.

The poster on Shotgunworld indicated the gun was " a 25 year old over-under Perazzi that has shot hundreds of thousands of rounds", which begs the question, at what point do you retire a gun? Also his load data is not what I would call a mild one, but he did say he used a PW press which reminds me of that long thread here a couple years ago when the poster blew up a pristine Baker. He used a PW press, and Clays powder, but what happened to that P-gun was unreal, not just a blown out chamber but total destruction. It had to have been the perfect storm: overload, stuck wad, weakened chamber. WOW.

Failure analysis cannot be conducted over the Internet by viewing pictures. It takes a trained Metalurgist, the neccessary equipment to first view the fracture surfaces under high magnification, then cutting of test specimens to verify the metalurgical properties of the material along with calculations and assistnace from both the gun and ammunition manufactures.
Since the shooter had mixed factory and reloads in his pocket, the highest probability is faulty reload. without conducintg a full scale failure analysis and knowing exactly what type of ammunition was involved it is not even useful to speculate, 'Pet Theories included.-Dick

This blowup, like absolutely every other one reported on the internet from the time of Al Gore's birth, involves a shooter who has lost or discarded all evidence that would explain the accident. This is not meant as a criticism, just a statement of facts. Weird, huh?

Here is anouther one that blowed up with Rem. factory loads. There has been several court hearings over this and test by Rem. this happened at a local club. Bill the owner is in his eightys and not in good health so i haven't persude it receintly. He was not injured when the gun blew up. Rich [img][/img]

No matter the root cause of the failure, the photo evidence indicates the event involved extreme pressure at the chamber. I'm guessing the pressures were above where the Bell Parker blew.

Someone on the other bbs suggested the metal wasn't ductile enough. Sheeesh! Look at all the deformation and chamber swelling. Another suggested a pre-existing crack caused this. Then why all the deformation and that fracture face? Why the split reciever?

I agree with Dick that you can't conduct a failure analysis based on pics across the internet, but these things are evident in the pictures.

Gentles,
I was never pointing the finger of blame at anyone, especially Gregsy.What I was trying to convey is that this problem of blowing up guns seems to have an exclusively American membership.Is that not good reason to look inward?If I can save one gun and one finger it will have all been worthwhile.I am not impressed when I visit your shooting grounds and men show me their scars and the piece of shrapnel that they keep in the glove box that did the damage.Impressed I am not.Horrified I am.

In discussions on this board of blown shotguns one often reads mention of factory ammo loaded to SAAMI vs CIP regs vs "low pressure" reloads. There is actually a 4th class of chamber pressures, what I will call "hot latino" loads. Here I include at least one Rio and one South American loaded Imperials, both in 67 mm 16 gauge hulls. In two instances, when submitted for measurement of chamber pressures and near-muizzle velocities, pressures were in 12000++ psi range and velocities about 1400 fps. How common are these high pressure loads?

At various times I have seen 12, 16 and 20 gauge Rio target ammo at attractive prices at trap and skeet clubs. Did all these Rio ammos also produce such high chamber pressures? Anyone have instrument pressures and velocities for Rio 12 and 20 gauge loads. They were sure popular. I also have reason to think (but not to conclude) that both Rio and South American Imperial shotshells are provided to foreign dove shooters enjoying those thousands-of-rounds-per-weekend shoots. Just how many of these "bullet proof", high dollar trap guns were subjected to unknown thousands of these hot latino loads?

Once one gets away from areas where shooters are native English speakers or Central Europeans, what is record of blown target shotguns and what are typical chamber pressures of factory ammos?

Niklas

Being an abesent minded kind of guy I am always worried I am going to swap powders. I am going to use a bulky powder receipe and accidentally load a dense powder. I have a Rex III low pressure sixteen gauge recipe and I use a MEC 33 powder bushing - if I remember correctly. My fear is my dumb ass is going to load Longshot by grabbing the wrong powder jar when I meant to load RexIII. When I load Longshot low pressure reloads I use a MEC 16 bushing.

Now I have a clearly marked jar for each powder but...

Best,

Mike

Hey guys... the discussion of SAAMI, CIP, reloads, etc is really not relevent to what we observe with these blowups. If Bell's tests showed anything, they show how tough even old guns are. The recent blow ups I've heard of involved some really fine modern guns, all proofed by either government agencies or the maker to at least 150% of normal pressure. It's likely that the guns will stand double, or greater, normal pressure before any signs of damage. They don't and shouldn't "blow up" with any reasonable load and most that are well past reasonable. I doubt that ANY quantity of correctly functioning modern smokeless shotgun powder that could fit in a shotshell would cause what we observe here. They usually survive even the dread 20/12 accident without the chamber failures we are seeing.

What we see is a detonation. The powder is not buring smoothly and progressively, it's releasing it's energy all at once. Like a grenade. The pressure spike is obviously enormous. This is an explosion to be sure... something is taking the shotshell out of it's normal operating range and turning it onto a bomb.

The story of the 101 on the Shotgunworld thread has my attention. Note the 'delay' before the gun detonated.

Have any experiments been conducted to simulate 'double ignition' of shotshells? The scenario I'm thinking of would be a faulty primer that burns in two phases. Phase one simply heats the powder charge up, phase two very shortly after ignites what is then a preheated charge. Is it this or something similar that causes detonation?

Perhaps someone with industry experience will comment.