Any chance a case-head failure would direct pressurized gas
into the hollow wrist of the polymer stock? Wouldn't take much to pop it, I bet.
Here's another possibility (again, going back to what I said about secondary and tertiary effects of a failure
not necessarily being the responsibility of design engineers looking to address primary failure mechanisms)
-Headspace is short ("manufacturing," not a "design" flaw), but OP manages to cram a properly spec'ed cartridge in their without the camming action of a turn-bolt (would be
very hard to close a break action with short headspace, btw)
-When fired, pressures skyrocket and the already razor's edge cartridge pressure shoots up above 100,000PSI and the case flows/ruptures at the breech
-Massive recoil experienced as a result once the bullet gets moving (kabooms are often associated with high recoil, even those not caused by overcharge)
-Massive recoil exceeds the safety factor limits of the stock design (this is where your alleged "design flaw"
might come into play)
-Sport-style stock puts the bore's line of action above the stock, so upon its breaking, the action lurches upward and back (the stock pitching up could cause injury as well as the rear of the action & stock edges)
-As the action pitches upward, the shooter's finger on the trigger contacts and disengages the breech lever, ultimately unlocking the action at some point during recoil (extremely likely this is
after pressures have fallen and the case failure occurred at the moment of ignition earlier on) OR the design of the T/C lever allows the recoil energy itself to knock the lever out of engagement (again, towards the end of or after the high pressure period, just like a recoil operated handgun)
The end result is that, from the shooter's perspective, they fired the gun and it sprayed them with case shrapnel, broke the gun in half, and the action was open or partially unlatched when they next looked at it. I can see how you would think the gun blew open, but it's entirely possible that the highest energy action (tens or hundreds of thousand PSI) was over before anything impacted your body.
Blaming it on headspace is, I think,
possibly misdirected. Perhaps not intentionally, but simply because headspace is a very relative thing; it pertains to a chamber/breech relative to the ammunition, and there are a half dozen or so mitigating variables between them. We shooters actually
do need to know or account for all of them before laying the blame on T/C (even 60% of it), otherwise causes like defective ammunition or SAAMI specs won't get the attention they deserve. Normally, I would
highly suspect any claim five thousandths of an inch would catastrophically rupture a cartridge, but this one
is at the higher end of the pressure scale, and is right on the edge of its brass liquefying with every shot as it is. I don't suppose this case had been fired one or more times previously, or full-length sized in the interim? If headspace was truly out as much as claimed, the brass should have been exhibiting stretch rings, loose/blown primers, stuck cases, and very difficult brass sizing; were these experienced?
I know it's good to get the closure of finding blame with a particular party, but the fact is the T/C design has been around long enough to be as proven as any action out there, so the idea that a massive safety flaw is inherent to the design is
extremely disturbing. We need to know enough details to determine exactly why this happened, so we can avoid it in the future on other designs drawing from T/C's art.
I would also not take T/C's subsequent redesign of the stock as 'admission' that their design was flawed. Through some unfortunate circumstance exceeding the design stress criteria, the stock broke at that location and a serious injury resulted. T/C engineers/designers determined that the product could be reinforced there to ensure that another overstress situation
beyond the scope of the design parameters would not fail similarly. It's called controlling the secondary failure mode, and it is not necessarily related to improper consideration for the primary failure mode (esp. if the primary is way beyond sane operational limits, like a double charge scenario; the designers can merely
attempt to limit the repercussions of failure at that point)
"The shooter got scoped real hard and in pain dropped the rifle on the rocks we see in the picture, thus causing the damage we see."
I'd say the odds of a simple drop breaking a polymer (?) stock in half at the wrist are lower than it resulting from a molding flaw or double charge and the
considerable recoil of a cartridge this powerful from a gun this light.
"I don't buy for one second the claim that he doesn't remember the important details of a trial that he thought was so important he's spreading the word of all over the internet"
Indeed.
"I'm thinking that if he really doesn't know the details, he should probably stop spreading the word... no knowing what went wrong in the first place and all"
Indubitably. Get his lawyers or experts to draft up a page-long summary of what went down if it is too technical (I'm
really not buying the "it can only be explained by thousands of pages of discovery notes" explanation, either
)
"The photo shows a stainless finish Encore laying on rock with the buttstock broken off, action closed, hammer down."
The lack of blood attendant to a serious eye/face injury on the ground/gun and neat photo composition suggests the photo was taken some time after the initial incident, possibly after its use of evidence at trial (I would have been careful to not wipe my blood off an object I was seeking product liability damages for, so I'm guessing after
). Once again, not enough info from the OP to reach any conclusion other than his assertions (funny that).
I move for a mistrial on the grounds that the prosecution has been withholding evidence from the forum (bad joke, sorry)
-----------------------
The reason I'm so interested in this is because I am currently designing and building original firearms actions as a hobby. Crap like this scares the bejeezus out of me. For Pete's sake, I hope to one day soon build a shoulder-fired anti-material rifle from a KPV action in 14.5x114mm (with proper tax stamps and complying with applicable laws, of course), and a failure like this one would straight-up kill the shooter --ME! You can't afford to be close with this stuff, and a 300WM is really not too far away on the lethal-to-shooter-upon-failure scale.
I've read of failures like this on wood-stocked big game rifles; the expensive ones with really curly burl wood are particularly bad about shattering in the worst possible place & injuring the shooter. That's why the 50 Alaskan bolt gun I'm doing has a stock with laminate construction and steel reinforcement running the length between layers; the stock bolts will sheer before anything lets go (and since the Steyr M95 is one of the action types that, as the OP alleges of the T/C, unlocks itself under the direct impingement of a ruptured case's gasses, I opted to use a lower pressure cartridge like Alaskan that clocks in at most 40,000PSI)
TCB
