Universal firearm mount

A system for coupling a red dot sight to a handgun, wherein the system comprises:

• a mounting unit, wherein the mounting unit comprises a single piece of material having:
• a male dovetail configured to be disposed in a female dovetail of a rear sight portion of the handgun;
• a tapped aperture extending through the male dovetail;
• a longitudinal rail above the male dovetail configured to receive the red dot sight, wherein the longitudinal rail defines:
• a plurality of lateral slots on the top of the longitudinal rail;
• and
• a longitudinal slot extending across the entirety of, and laterally centered on, the top of the longitudinal length of the longitudinal rail;
• two visual markers on the back of the longitudinal rail, one to the left of the longitudinal slot, and one to the right of the longitudinal slot;
• and
• a set screw disposed in the tapped aperture, configured to selectively impact the bottom of the female dovetail.