The Double Alpha Mini Mr. BulletFeeder 6-tube magazine assembly allows you to preload another 100 bullets before you start your reloading session. Once the assembly is filled make sure to keep it in a upright position to prevent the bullets from tipping out of the top holes. Align the hole in the base of the unit with the tube, which has the retention pin in place, so that all 6 tubes can be filled. Once the assembly has been placed on top of the dropper die assembly, then remove the pin to allow free flow of the bullets into the dropper. This can be used on any progressive reloading machine which uses the same size dies as Dillon., however please note that the powder funnel supplied with it is designed to be used ONLY in the Dillon powder drop.