Firing pin removed and cavity filled with hot lead
Barrel similarly filled
Trigger locked
Action welded immobile
Magazine can be inserted and removed but that’s all
Objective is to render the gun inoperable and irreparable, but without changing the outside appearance.
There IS a market for all matching deactivated pieces- no permit needed, nice display item

Also displayed in museums and used in re-enactments.
Different culture here! Enjoy the 2nd Amendment!!
MURDER you say? Yup! First degree and premeditated