Good question Kevin, Simply put, don’t believe half of what you are reading. Your arrows @ 400 grains being shot @ 245 FPS is giving you 86.95 kinetic Joules of energy. That is almost twice enough to take a whitetail deer. Most broad head manufacturers will say say a minimum of 45 Joules of kinetic energy is needed to kill a whitetail. I have used many a bow with much less energy than what you are currently using to take whitetails. So have confidence your bow can do the job....but most important practice, practice and practice some more as shot placement is critical for an ethical kill.

If anyone is interested go to archerycalculator.com and this handy tool can tell you how much kinetic energy your bow is shooting. Enjoy!

 

Good question Kevin, Simply put, don’t believe half of what you are reading. Your arrows @ 400 grains being shot @ 245 FPS is giving you 86.95 kinetic Joules of energy. That is almost twice enough to take a whitetail deer. Most broad head manufacturers will say say a minimum of 45 Joules of kinetic energy is needed to kill a whitetail. I have used many a bow with much less energy than what you are currently using to take whitetails. So have confidence your bow can do the job....but most important practice, practice and practice some more as shot placement is critical for an ethical kill.

X2 Educator. Put about as clearly as it could be stated!

 

Good question Kevin, Simply put, don’t believe half of what you are reading. Your arrows @ 400 grains being shot @ 245 FPS is giving you 86.95 kinetic Joules of energy. That is almost twice enough to take a whitetail deer. Most broad head manufacturers will say say a minimum of 45 Joules of kinetic energy is needed to kill a whitetail. I have used many a bow with much less energy than what you are currently using to take whitetails. So have confidence your bow can do the job....but most important practice, practice and practice some more as shot placement is critical for an ethical kill.

If anyone is interested go to archerycalculator.com and this handy tool can tell you how much kinetic energy your bow is shooting. Enjoy!

Thank you!

 

I dont know how Joules are calculated or exactly what they are but a 400gn arrow at 245 fps will give you. 53.26 ft lbs of KE . At least thats what I believe the form of measurement is for this calculator. I'm sure you have enough to kill a deer. With that said your Ke numbers go down the further away your target is. This is where extra weight can be a big help giving you more momentum. Here's the calculator and some articles on the subject Kinetic Energy and Momentum Calculator

 

Your absolutely correct Stalker, 53.26 is correct, I need to put my glasses on in the morning when using my phone to answer with. I swapped around the numbers ..old age bites....

For more information on Kinetic Energy and Momentum, please see

Kinetic Energy, Momentum and Arrows
Probably more than you are looking for, but here is your answer on how KE is measured ( taken from the Archerycalculator.com website):

The kinetic energy (KE) of an object is the energy of the object due to its speed and mass. In order for the energy of an object to change, work must be done on the object. In the case of an arrow and archery, work is done by the archer’s muscles by pulling back the string and flexing the limbs. The energy is stored in the limbs in the form of potential energy; when the string is released the energy stored into the limbs is released, most of which is absorbed by the arrow.

The energy not absorbed by the arrow becomes friction in the bow parts, noise, vibration and other inefficiencies experienced by the bow. Energy that is absorbed by the arrow is converted into multiple forms, the majority resulting in the forward velocity. The kinetic energy of the arrow that archers care about and calculate is the energy due to its forward motion. As the arrow travels downrange, the total energy diminishes mostly due to air.

The standard formula for kinetic energy is:

 

Kevin your bow will kill! Welcome to CBN.