shooting 60 lbs, with a 300 grain arrow, your speed is not limited....60 lb X 5 gr per lb = 300 grain arrow. this is usually not a problem with longer draw lengths, over 28 inches. the shorter draw has always been at a disadvantage, real or percieved. now you can shoot a 100 grain arrow at 60 lbs, as long as you do not exceed 280 feet per second. these rules are meant to keep you safe. shooting lighter than 5 grains per pound is hard on equipment. most manufacturers use 6 grains per pound, but will still advertise ibo speeds.