So here’s the rub and it comes down to the difference of what “can” be done and what “should” be done. Can a 500 FPS airgun kill a squirrel? Under the right circumstances, and with enough shots, sure. But, is it the right airgun for the job? Not in my opinion.
FPS vs FPE
Let’s start with FPS (feet per second) as that’s what manufacturer’s use to promote their airguns. Unfortunately, FPS can be manipulated very easily by simply changing the weight of the pellet. Reduce the pellet weight and the FPS will climb. This says nothing about accuracy, just raw velocity. It also does not address effectiveness on game. It’s a play on the consumer’s psyche that faster must be “better.” Any seasoned airgunner will tell you that this is often NOT the case.
FPE or “Foot Pounds of Energy” is a far more effective measure of how an airgun will do in a hunting environment. But, that’s still only part of the story. FPE is an approximate measure that takes into account the velocity and the weight of the projectile. (click here for an FPS to FPE calculator!) It refers to the amount of potential energy that could be transferred into the target when the projectile hits its mark.
I’m using terms like “approximate” and “potential” for good reason. The most popular airguns are entry level .177 caliber breakbarrel airguns. They are very inexpensive to acquire and ammo is very cheap. But, the very small projectile tends to simply pass right through small game. This imparts very little energy into the game and often leads to wounding rather than humane kills. Accuracy is often an issue with the lesser expensive .177 airguns as well. The kill zone on small game is well, small. I’ve seen a squirrel take several shots from an inexperienced shooter to finally finish the job. It was very hard to watch.
If an appropriate FPE is only part of the story, what components make up the other parts?
FPE is a key component to an airgun’s potential effectiveness. The other components are accuracy and caliber, respectively. Accuracy with any caliber, given it has the necessary FPE, will be effective. Smaller calibers require great skill. When you increase the caliber size from .177 to .22, .25, .30, .357, .45 and upward, then the precision required for a humane kill decreases.
There are some calibers that are very well suited for various types of game. The general rule in the airgun world has always been .177 for feathers and .22 for fur. However, this was speaking solely in the small game arena. As airguns, specifically large bore airguns have become more popular, the “fur” category has grown dramatically. And, more and more states have recognized this by providing specific rules and provisions for hunting larger game with airguns.
So what kind of FPE should you use for various game?
First of all let me state that while I’m familiar with many types of airguns and their capabilities, I am new to the airgun hunting arena. With that said, I have drawn upon the experts regarding the following suggestions and it’s what I’m going to use as I explore my new found love of airgun hunting. Given the variety of airgun calibers and potential game, I’m going to break this down into game, caliber, kill zone, and energy. This will probably be a “living” chart which I will update as new information becomes available. It also assumes the ability for the airgun and shooter to effectively hit the necessary kill zone of the intended target.
Game | Minimum Acceptable caliber* | Kill Zone** | Minimum Energy |
Small Birds | .177+ | .5″ | 5 FPE |
Medium Birds | .177+ | .75″ | 7 FPE |
Large Birds | .22+ | 1″ | 11 FPE |
Squirrel Sized Game | .22+ | 1″ | 9 FPE |
Rabbit Sized Game | .22+ | 1″ | 9 FPE |
Raccoon Sized Game | .22+ (.25+ recommended) | 1.5″ | 25 FPE |
Possum Sized Game | .22+ (.25+ recommended) | 1.5″ | 25 FPE |
Fox Sized Game | .22+ (.30+ recommended) | 1.5″ | 35 FPE |
Coyote Sized Game | .30+ | 2″ | 50 FPE |
Javilina Sized Game | .357+ | 2″ | 90 FPE |
Small Deer | .357+ | 2″ | 100 FPE |
Medium Deer | .40+ | 2.5″ | 150 FPE |
Larger Deer | .45+ | 2.5″ | 200 FPE |
Hog | .45+ | 2.5″ | 200 FPE |
*Minimum acceptable caliber is based on suggestions from the experts in the field and my personal experiences. It’s critical that you check your local hunting regulations for their various requirements for taking game animals with airguns.
**Kill zone size is determined by either an effective head shot or shot to the vitals that should facilitate a clean, 1 shot kill. The kill zone size will vary based on the size of the game and these values are given as a very basic guideline.
Final thoughts
Remember, that when hunting with an airgun, precision is EVERYTHING. You have to be able to reliably hit that kill zone or you should not take the shot. In my recent trip to TX I learned very quickly that my bench skills did not translate to hunting effectiveness. Fortunately I did not have any wounded birds on my hunt. Because I was using a heavier than necessary caliber with more than enough energy, a hit equaled a clean kill. This is definitely something that I’ll remember for my next trip out in the field.