Anyone ever used 777 in their 45-70? I have been loading smokeless for about 13 years now in my 45-70's and was wenting to try something different in my Marlins. I have been using 3031 for my different bullet weights. Been having awesome results with some 420grain hardcast flat nose bullets and was wanting to keep them in the 1600-1700 fps range. Is this possible with 777? I put some in a case to where the bullet would give mimimum compression and weighed the charge and came up with 55 grains of powder. Is this enough powder to get me the desired velocity? I did not want to compress too much. I have heard the blackpowder subs do not like compression like Goex does.