I never use more than 100 grains of anything 777 , Pyro or BH . I don't care if my Muzzy is a magnum or not . After shooting 100 grains of pyrodex in the winter and seeing Black powder all over the snow with my encore ( 26''' barrel ) i dropped my load to 90 and had nothing on the snow and that was with a 300 grain bullet . I bet most of the powder over 90 grains is going out un- burned with 26'' barrels and anything over 110 grains with 28'' barrels . IMO.