since the Op's title was 'relying on' vintage arms, I would add that a concern with metal fatigue and age is a crucial factor in relying on an old gun.
those in aviation understand the boneyard concept, to be a place where old aircraft are retired since the service life of the parts has been reached and the airframe has met its limit for safety.
down at the molecule level is where the concern needs to be focused, much like welders that have their work inspected with x-ray.
old vintage guns in some cases may have reached their limit and are just waiting to fail, putting you in harms way.
heck, when I was in the teams, the sig226 had a rebuild cycle of 20,000 rounds to avoid frame cracks...and at 100,000 rounds it was sent back to the factory and replaced.
old unserviceable rifles in ww1/2 had their bbls welded closed or cut and the bolts bent to discourage owners from reviving dangerous arms.
I collected 1974 Winchester sxm1 shotguns. brand NIB guns failed right out of the box just from sitting. so you cant use the NIB title and be safe either.
as I was taught in corrosion control training in military aviation, 'metal is
constantly returning to its natural state and can only be delayed.'
when you run your hands along a vintage gun at a gun show....do you REALLY know the round count or how abused it may be? some gamble. some don't.
its a crap shoot.
but count me in to depend on old iron, than new...or plastic/alloys.
ashes to ashes, dust to dust.
amen.
