What is the minimum speed I need to shoot to open the blades on a Spitfire?
To consistently produce efficient penetration, we recommend about 50 ft/lbs. of kinetic energy when shooting Spitfires for deer-sized animals and about 55 ft/lbs. for larger game. However, there really isn’t a minimum speed requirement to open the blades on a Spitfire. We have shot very slow, lightweight arrows into foam from a 5-pound bow and the blades opened consistently. The question is more related to kinetic energy and the ability of the arrow to penetrate efficiently. Kinetic energy is the measurement of the force that is produced or changed when a mass is put into motion. For the purpose of archery, we measure kinetic energy in foot-pounds (ft/lbs.) For those of you who would like to calculate the kinetic energy of your bow, read on. To calculate the kinetic energy of your bow, use the following equation: (Arrow Weight in Grains)(Velocity)(Velocity) = ft/lbs. 450240 Notice that speed or velocity is part of the kinetic energy equation. However, the weight of the arrow is another
