The silencer model was made by Millenia. Unlike previous mods, this one lacks of custom sounds, because I thought the original sound was just fine. However, I’ve got the sounds of the silenced Luger P08 of Indiana Jones and the Emperor’s Tomb, if you’re interested in those, request them by private message in GTAForums (but keep in mind the P08 is 9mm, and the M1911 is .45, so it won’t be too accurate).
Credits:
LeatherJacketSoldier