Now is the perfect time to get into archery. We are still 6 months away from deer season and if you pick up a bow or crossbow now, you will have plenty of time to practice with it. You will increase the amount of time you have to hunt and gain the ability to hunt the best part of the rut (early November). Selecting a bow or crossbow can be overwhelming. I’ll get into some more detailed recommendations soon. For now, though, I want to cover a question I get asked a lot: How much weight do I need to be able to draw to hunt big game?

Kinetic Energy

This section is going to get technical for a minute. If you just want the conclusion, skip to the next section—I will think no less of you.

The concept of kinetic energy is an important one when talking about hunting. It is a measure of the energy in foot-pounds that a projectile will impart. The equation is KE=1/2mv² where KE = Kinetic Energy, m=mass and v=Velocity. Mass is equal to weight/gravity. We want our answer in foot-pounds so we will need to convert our common ballistic weight unit of grains to pounds. Then the weight (pounds) needs to be divided by 32.2 ft/s which is the pull of gravity. Without getting too deep into the math of it, just know that the energy of a projectile is dependent on its mass and velocity. Because velocity is squared in the equation we know that the speed of an object will impact the kinetic energy at a greater rate than its mass.

So, when talking about the energy an arrow or bolt can impart on an animal we are hunting we need to know the speed that a bow can shoot and the weight of the arrow (weight of arrow and broadhead). We will measure the kinetic energy in foot-pounds.

Here is a good calculator for Bow speed (you will need to know your draw length, bows IBO speed, arrow weight – including broadhead) that allows you to calculate how fast an arrow of a specific weight can travel for what your draw weight is set at.

What Kinetic Energy Do I need to Hunt (insert animal name here)

Conclusion – What Bow Or Crossbow to Buy

To break this down, if you are hunting deer, any modern new adult compound bow that you can draw at 45 pounds is going to be sufficient for hunting deer, black bear, and elk. Just about every healthy adult and most teens should be able to draw 45 pounds. Buy a compound you feel comfortable with and have it setup for you at a decent archery shop. The setup is going to be critical to ensuring you can shoot it well.

As for the crossbow, even the cheapest adult crossbow will be capable of producing enough kinetic energy to hunt big game. Just look for a crossbow that you can safely draw and one that shoots at a velocity of at least 280 fps.

Note: Kinetic energy is not the only factor that is important in hunting with archery equipment. Because the object with archery hunting is to cause blood loss, other factors like the type and dimensions of your broadhead, and the FOC (front of center) weight of your arrow will also be important.