I missed this post the first time around 3 years ago but have a 40 Browning but no one has mentioned having the HP-SFS (Safe-Fast-Shooting) variation on the Hi-Power Mark III modified firing mechanism.
Basically after the weapon is loaded to make the gun safe the hammer is pushed forward with the thumb which automatically activates the safety lever.
When the shooter is prepared to fire, the safety is pressed down releasing the hammer to spring backwards into the single-action position, Really neat system.