MakerShot Simple Loader - Single Stack Magazine Speed Loader Step 1: Select your magazine style (single stack or double stack) and # of loaders above. Step 2: Verify your pistol compatibility below. Single Stack Compatibilities: Smith & Wesson 22a, Victory ; Beretta U22 Neos ; Browning Buck Mark ; Ruger Mark I, Mark II, Mark III, Mark IV, 22/45, 22/45 LITE.