My understanding of it is the 777 is more powerfull then the pyrodex. SO what there saying is 60 grains of 777 is about 85 grains of pyrodex. I am assuming these are volume measurements. As they would weight differnt because the mass is higher then the weight. From what i read and what everyone is saying use two mag. pellets of 777 in place of the 3 pellets of pyrodex. I am new to this so i may be wrong