DLH-If it is in good shape, and a 20ga, I would suggest about 60gr 2fg and a .600 roundball to start. I know 60 gr sounds like a small charge, but you would be surprised what that big ball going at low velocity will do at smoothbore ranges. It may need more powder to get it to print a decent group or maybe a tighter ball/patch combo, but start low and slowly increase, your safety is YOUR responsibility. In a 20ga. Fusil deChase I had, I used 70 gr 2fg and a .595" ball with heavy denim patch, (heavy denim so as not to burn out) and it shot pretty darn good out to 60 or so yards. Good luck with it. Ted K.