[turnpike boy]

Cryogenics is used in the gun trade pretty steadily, principally on barrels but for receivers, interior parts, etc. as well. Similar in approach to heat treating - aim is to bring molecular structure into a more uniform state - but without the restructuring/alteration/modification of the molecules themselves that can happen in less-than-perfect heat treatments. In a nutshell, it's supposed to make harder, stronger, more uniform grain structure in the metal. I suppose I'll get arguments about this, but I think proper heat treatments work substantially better. Want a hard crank surface? - nitride it.