In the early days of Star Fleet, there were no formal security commands set up on exploration vessels, so the armory officer was often in charge of both tactical station functions and those of shipboard security. Many early policies of Star Fleet security and tactical weaponry procedures were set in these early missions. The terms "armory officer" and "tactical officer" were used interchangeably, as the two jobs were occupied by the same person.
The involvement of armory personnel in security operations lessened as MACO troops were assigned to Star Fleet vessels during and after the Xindi conflict of the 2150s. Some functions of this department would in later years evolve into the modern Star Fleet Security department, where many of the same roles played in the Earth Star Fleet would be assigned to the position of Chief of Security – which is sometimes occupied as the same individual who is Chief Tactical Officer.