Not sure if this has been posted but thought it was cool. Was pretty surprised how long the barrel and everything else lasted under the conditions.

https://www.full30.com/video/f8a39753e6950ee1a11d02b1d7a2fa7c?ref=SV

Colt did that with their M4s when there was reports of rifle failure during a super long fire fight in Iraq

They compared M4 barrel contour which burst after 535 rounds, and the M4-A1 barrel lasted 911 rounds when the gas tube broke. It would still cycle manually and fire after that.