I read in some threads that the right bow equipment is a 80 to 90 # Bow with an 800 grain arrow. This can be right, but it must not be. A friend me use an 5 years old bow with 90 # and an arrow with 800 grain. His draw length is 27". I use an 70'# Destroyer. My draw length is 30" and the arrow weight is 777 grain. The speed of my bow is 238 fps, my friends 215 fps. What will I say: not alone the # are important, look for the IBO speed of the bow. New bows have 330-360 IBO. Older bows only 290-310. Look for your draw length Is big speed difference between 25" and 30" 1lbs dw is only 2.5ft., but 1" dl is 10ft.! At last, forget the KE, it is only a physical formula. For penetration use only the MOMEMTUM formula.