This could have ended a LOT worse

[jakelly]

I can almost agree with you completely. I don't feel the load was entirely experimental. As I stated, I followed the powder manufacturer's instructions closely, and have fired at least 30 rounds of this load in this gun without incident. That's in addition to the rounds fired during load work up. I don't know how many rounds you think it takes to "prove" a load, but in my mind it was no longer experimental.

I didn't gather that initially. Yeah, in that case I would have considered the load proven. Scratch that one off the list.

 

[asd9055]

It was the Norma lab. Testing 50BMG and 20mm cannon powder, which are a powder similar to US869, US970 etc, which are a canister powder but swing in burn rate too much to be sold to the general public.
Contrary to people's observations and assumptions, to be sold as a canister grade powder, it MUST stay within +/- 3% of the ORIGINAL powders burn rate as shown in a calorimeter bomb, if it falls outside of these parameters it can ONLY be sold as BULK.
People bandy about that powder in canisters are blended…no they are not.
Worked where it's made, if it doesn't come up to snuff, it never sees the shelves. Believe me, when we're talking a train load of powder, they're striving to get that powder the same every batch, because bulk powder gets bid on, not just sold at a particular price point.
Anywoo, there you have it.

Cheers.

Thank you! I appreciate you taking the time to explain! I learn so much on this forum!

 

[jakelly]

It was the Norma lab. Testing 50BMG and 20mm cannon powder, which are a powder similar to US869, US970 etc, which are a canister powder but swing in burn rate too much to be sold to the general public.
Contrary to people's observations and assumptions, to be sold as a canister grade powder, it MUST stay within +/- 3% of the ORIGINAL powders burn rate as shown in a calorimeter bomb, if it falls outside of these parameters it can ONLY be sold as BULK.
People bandy about that powder in canisters are blended…no they are not.
Worked where it's made, if it doesn't come up to snuff, it never sees the shelves. Believe me, when we're talking a train load of powder, they're striving to get that powder the same every batch, because bulk powder gets bid on, not just sold at a particular price point.
Anywoo, there you have it.

Cheers.

Well, if it can be reproduced in those circumstances, at will, then I'm not willing to bet my body/property/life that it "can't" happen to me in my circumstances. The hypothesis driving this detonation research comes from people who have experienced it. You seem to be arguing that this can't or doesn't happen, evidence suggests it does.

In the spirit of not derailing the thread further, I do not think that is what happened here. Every indication points to brass failure not a pressure event. This has it's own lessons and I stated to the OP what I would do differently.

If there is a takeaway that I would like to stress for the sake of posterity, it's not that reduced charges can lead to detonation pressure spikes, but rather that the bolt being on the wrong side is more than just mildly inconvenient. I'm a LH shooter and this is somewhat personal, but objectively it's reckless. It's not a big deal, until it is, and then it becomes really big, as this instance clearly demonstrates. My rifles are all LH and my RH shooting children all get RH rifles. Yes, it's another expensive purchase, but I would have a very hard time forgiving myself if one of my children lost an eye or worse. Thank God this girl is fine, truly could have been much worse.