Butler Creek ASAP Pistol Loader, Loads Most Single Stack Magazines, 9MM-45 ACP, Polymer, Gray BCA1XSML The ASAP Universal Single Stack Magazine loader works with a large majority of single stack magazines between 9mm - .45 ACP. Fill magazines with one action - push the mag loader down" insert the round below the feed lips" and raise the loader up. Bullet seated; magazine loaded. Just like that.