spent case temperature difference - Page 2

stagpanther · August 20, 2016, 04:31 AM

Quote:

Maybe it's even simpler. Whatever isn't turned into the kinetic energy is going to be heat. Now all we need to do is determine exactly how much chemical potential energy there was in the charge, subtract energy at the muzzle, collect and measure the energy that a.escapes with the flash, account for the energy lost to bore friction, and we will be left with a truly useless number that will not even remotely come close to what heat remained in the chamber.

My wife tends to ask me "science" stuff, and Lord almighty, it's hard to tell her that even "science" has limitations. Of course we know what the moon weighs. The astronauts weighed it back in the sixties.

Post of the month contender.

Mobuck · August 21, 2016, 07:53 AM

" I know the AR sends gas back into the receiver--but I still don't see how that can account for such a marked difference. "

I don't think you can use that idea. While doing a preliminary zero on my new piston AR(no gas in the action), I grabbed a case that missed the brass catcher and was rolling off the bench. It was every bit as hot as the one fired by the DI AR I'd just fired that bounced off the spotting scope and landed on my hand.

August 21, 2016, 07:53 AM	#27
Mobuck Junior member Join Date: February 2, 2010 Posts: 6,846	" I know the AR sends gas back into the receiver--but I still don't see how that can account for such a marked difference. " I don't think you can use that idea. While doing a preliminary zero on my new piston AR(no gas in the action), I grabbed a case that missed the brass catcher and was rolling off the bench. It was every bit as hot as the one fired by the DI AR I'd just fired that bounced off the spotting scope and landed on my hand.