Most often practiced in
IDPA, the
tactical reload is different from the ordinary
magazine change with retention in that the reload
must be performed "at the gun".
This means that you first need to draw your other charged magazine, bring it to your sidearm, remove the spent magazine without dropping it, load the new magazine, and put away the spent magazine before continuing the course of fire.
This method leaves you with a single shot sidearm the smallest amount of time and is the preferred method of reloading in realistic competition like IDPA or in a real life shooting scenario.
Although some people prefer the magazine change with retention as it has a smaller chance for the shooter to drop a magazine, the tactical reload is considered to be "better" and can be substituted for a magazine change with retention in a mandatory reload part of a course of fire, the reverse is not true.