"Somebody had a lot of trouble on this stage", he said. "Looks like his ammo blew up, and it locked up his gun for a while. I'm thinking ... double-charge of powder."
I was only mildly curious at the start, but once I looked at the cartridge case I had to agree.
In the first place, the case was dramatically bulged on one side, which suggests not only an overcharge but also that the case was fired in a barrel without a fully supported chamber.
When I looked at the base, I saw more signs of abuse. The headstamp was almost completely obliterated, which suggests that this case had been fired so many times that the headstamp was eroded to the point of being erased. That's not a problem with the base, which is the strongest and thickest part of the cartridge case, but it does suggest that excessive reloading may have caused the sidewall of the case to have been weakened.
On the other hand, is it possible that the headstamp may have been partially obliterated because the pressure of the overcharge (?) pressed the base of the cartridge against the breech so fiercely that the headstamp was malformed?
Looking at the case more closely, the case didn't split; it wasn't an 'explosive' KaBoom, only the kind of situation where the case can be jammed in the chamber and cause the shooter a delay in completing a stage while he strives to extract a bulged cartridge.
As evidence of the problem, take another look at the cartridge base. The missing primer is an almost certain indicator that the cartridge was overcharged. The only other condition which would cause the primer to be ejected from the cartridge case is if the case had been fired so many times, the primer pocket had eroded or expanded ... allowing the primer to be ejected when the cartridge was fired under 'normal' pressures.
In this situation, if the primer was only loosely held in the primer pocket, the pressure would probably not have been contained to the point that the case wall was bulged. (This isn't an infallible test, it depends on the timing of the pistol; if the wrong size link is used in a 1911, the release of the slide to recoil may have been delayed to the point at which the pressure built up too much on almost every shot. But this would suggest a number of KaBooms.)
The final information to be gathered by examination of the case is that the base shows not one, but two places where the rim of the cartridge has been obviously deformed by slippage of the extractor, which probably left the cartridge case jammed in the chamber.
We would have expected one such sign of extractor failure, but two of them suggest that this is the second time this case has failed.
I don't believe that; I don't think that a blown case was reloaded, and I don't believe that extractor slippage happened twice on exactly opposite sides of the base on the same cartridge.
But I would appreciate the contribution from a more knowledgeable reader to explain the diametrically opposite marks on the cartridge base.
Or is there a Forty Slow and Wimpy pistol on the market with dual extractors?
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We've made a lot of assumptions based on a minimal amount of real data. Anyone who can claim more technical expertise is invited to contribute here.
Enquiring people want to know. Please respond in Comments.
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