MOST Smith and Wesson Series 59 magazines do work in the P-11 just fine by Kel-Tec design, and also maybe the Daewoo DP51 9mm pistol. They will stick out of the bottom of the frame a bit. The Daewoo .40 cal mags I know nothing of......................elsulloYeah I was excited to find and purchase it. Funny thing was I was out looking for vinyl records that day and ended up finding the P-40. Now just have to get another magazine and some ammo for it.