Reverse-saboted sidearm systems, and related sidearms, ammunition, and methods

A saboted ammunition round, comprising:

• a casing exhibiting a non-necked cylindrical exterior extending from a striking end to a discharge end, the casing defining an interior, the discharge end having an aperture defining an opening, the opening communicating with the interior;
• propellant disposed within the interior;
• a primer mounted at the striking end of the casing, the primer being operative to ignite the propellant;
• a sabot mounted at the discharge end of the casing, with a first portion of the sabot extending into the opening and the interior, and a second portion of the sabot extending outwardly from the discharge end of the casing, the sabot exhibiting a diameter corresponding to a diameter of the opening of the casing and defining a receiving passage aligned with a longitudinal centerline of the casing, the receiving passage extending through the sabot from a proximal end of the first portion to a distal end of the second portion;
• and
• a projectile disposed at least partially within the receiving passage of the sabot;
• the casing, the primer, the sabot, and the projectile encasing the propellant;
• wherein:
• the sabot is a first bullet of a caliber configured for use with the casing;
• the receiving passage is formed through the first bullet;
• the projectile is a second bullet of a smaller caliber than the caliber of the first bullet;
• the projectile is a 5.56 mm NATO rifle bullet;
• and
• the first bullet is a 10 mm auto pistol bullet.