Post mortum LE bolt failure...

[Ridolpho]

With apologies to the Moderator for helping to keep this going, I'm curious- does a pierced primer not potentially allow for direct communication with the very high pressure volume within the bore? Flow into the bolt head would be controlled by the very small perforation in the primer (orifice or choke) but consider the energy obtained by tapping off gas well down the bore in actions like the SVT or G/K43. The G/K43's, in particular suffer from severe pounding in the bolt/ carrier. I believe I see gas vent holes in both No.1 and No.4 bolt-heads so is the main consideration here that these are large enough to deal with any conceivable flow into the bolt from whatever? It's not like this issue wouldn't have occured to the designers!

Ridolpho

Information

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[303Guy]

You got me there! I have no reason to disbelieve the fellow but no, I am not absolutely sure. He does present as a straight talking guy. I'll keep looking for verifiable evidence. Anyway, he said the striker shaft broke off behind the collar. I asked and he didn't answer so I don't feel free to quote him.

By the way, it is comforting that you armourers have not heard or seen this sort of thing before. My first thoughts when I hear about this sort of thing are, "oh heck, could this happen to me?"

But here's a thought; if a primer ruptures at 48,000 CUP, the force acting on the striker could be as high as half a ton (as unlikely as that may be). Thinking about it, if high pressure builds up inside the bolt, the striker could be driven back quite fast providing a hammer effect when it reaches the end of it's travel. And we all know what shock loads can do to hard steel. Ever had a chisel fracture and drive a shard into your ribs? I haven't, thankfully but know of a few instances.

[Peter Laidler]

You are right OldPaul - so far as it goes, but I am considering the theory in this instance whereby it is alleged that the volume/pressure of gas that could vent back through the two fire holes of the main 'explosive' chamber of the cartridge, back into the primer chamber and THEN back through the pierced primer cap into the bolt and....... and....... When we already know that the vol. of gas generated by the primer might cause a re-cock. But we're talking about a volume of gas that drives the striker rearwards out of the bolt and all that that entails.

Look 303Guy, this ain't not going to happen, believe me!

[5thBatt]

Don't know why i bother replying to these threads as i just collect the bloody things but (& most probably a stupid question but please humor me) if there was enough pressure forced back under normal firing conditions that could violently force a cocking piece backwards though a pierced primer would you not expect a percussion cap to be blown off & hammer thrown back (or does this actually happen) every time you fired the likes of a old percussion Enfield??

[bigduke6]

Don't know why i bother replying to these threads as i just collect the bloody things

If we didnt reply I think it would be a boring forum....

[tbonesmith]

The best thing about this forum is the level of factual information about the specific firearms we discuss, collect and use. The problem with threads like this is the level of speculation and opinion that may be half correct, unclear or untrue.

I don't want to see too much unsubstantiated opinion, or vague descriptions of circumstances that may confuse facts or confuse newcomers.

By all means discuss what you want, but this is getting pointless, and I will close it soon if it continues like this.

Cheers

Tom