I have some ordered but not here yet. I have had really good luck with Blackhorn 209 but I am not going to pay 180.00 $ per pound for it, I just refuse to do so. I understand that the Shooters World MPB s the same powder as Alliants Black MZ which I have never used, or even heard of until recently. Blackhorn 209 is actually a smokeless powder with something that smokes a little added to it. I always shot Blackhorn in 45-70, 45-90, 50-110, 50-95, 40-82, 40-65, 45-60, 40-60, and 50-100 in loads by the grain with a Walters .060 wad on top of the powder without the thought of using fillers since it is a smokeless powder and my reloads with cast bullets (20:1) and Federal 215 primers have performed to my satisfaction. Question is with Shooters World MPB has anyone heard that it is actually a smoking smokeless powder like Blackhorn and if not does it require fillers to fill space not occupied by the propellant powder? Thanks for your input. Dr.C