Micro-printing is a total waste of time.
Fire around 500 rounds thru a gun, sometimes less, and the FP mark is history.
It simply wears off.
Now as far as ballistic fingerprinting, any idiot who has watched their Crime Shows knows that
cops can match the lands & grooves on a bullet to a barrel. (Assuming the bullet wasn't totally deformed)
So, if you plan on being a hitman, if you have a lathe, you have an INFINITE source of new barrels.
Kill someone, melt the barrel down, grab one of your pre-made ones, and go smoke another target.
If you don't have a brass catcher already, tie a Crown Royal bag over the ejection port
If California & other places want less gun crime, simply use Florida's 10-20-LIFE law, CCW, & Castle Doctrines.
It cut WAY down on our crime rates...if the crooks weren't killed by their victims,
or put away for life in prison...they simply left for easyer hunting grounds...like Cali, NY, NJ, & Ill