 These were accompanied by the cord pulley spanning device.However, the power stroke of the European crossbows remained much lower than that of Chinese crossbows (typically one third of the powerstroke), which limited their power despite increasing draw weights.For example, a draw crossbow with an powerstroke can shoot a 400 grain arrow at 205 fps, while a 150-pound draw crossbow with an powerstroke can shoot a 400 grain arrow at 235 fps.