Originally Posted by
gloob
I figured you'd have deleted that post, by now. I never did quote it, so as to give you that chance after giving it 10 more seconds of thought.
You, yourself posted this, right after.
Yes, you can start a fire by rubbing two sticks together. But if you do that at the same time as burning 10 grains of smokeless powder under your tinder, you might want to give some credit to the powder.
Measure the temp of your chamber while you're at it. Notice it heats up, too, but it will never get as hot as a freshly auto-extracted case. The chamber cools the case.
You could also try extracting an empty case out of your gun over and over. Tell us how hot it ever gets.
Giving physics lessons always goes wrong, on a gun forum. I know better than to try, but here I am:
Barring some potential extra friction from early/sticky extraction, the total amount of heat created by extracting a case slowly versus quickly is the same. This is the reason boolit friction can't make an entire boolit turn to mush, no matter how fast you shoot it (keeping barrel length constant). Faster velocity just means that same amount of heat from friction is dumped into the skin of the boolit in a shorter time, potentially softening/melting the skin before that heat is shared deeper into the core, and then allowing gas to jet past and melt the entire boolit. Higher psi will more likely force a leak and higher psi means the jet is faster, thus hotter (replaced by more hot gas as fast as that heat is absorbed by barrel/boolit).
I.e., if a substantial enough portion of the boolit melted/eroded to cause accuracy issues, that bullet leaked, period.