Geezer here: Is a 170 lb. prod too heavy to pull by hand? In my experience, most adult men can pull a prod of that weight, by hand, but as you progress beyond 150 lb. the work gets harder to justify without a cocking device. So yeah, I used to shoot a 180 pounder at local SCA meets, but honestly, it made my back and shoulders sore pretty quickly, and repeated spanning builds up lactose in muscles, so you get shaky. I recommend if you're gonna shot a bow in excess of 150 multiple times in an afternoon, you should consider getting a simple spanning device, like cord/pulley or belt-hook. Your accuracy will be better and you'll have more fun. So it's not how much you can pull by hand, but how much you want to pull over and over and over and... well you get it! Geezer.