So type and HT of the steel doesn't make a difference ?? About 80 years ago they introduced the high velocity 22RF.Colt pistols were marked to indicate pistols designed for the higher pressure load.
Using the older guns with newer ammo wouild reduce the life of the gun. Even a modern pistol using lower pressure standard velocity will last longer than if using the high velocity.
In the 70s there were obvious differences in the "quality " of pistols. My Browning Challenger wouild outlive a High Standard. Don't know the specifics but steel type and HT was obviously the thing that made the difference. BTDT, I am a metallurgist after all !