Energy, accuracy and pellet performance for hunters

by Harley Ayre

Muzzle energy is something new airgunners should become familiar with, because it is far more significant than muzzle velocity. When Daisy was being sued for a wrongful death due to improper design of one of their airguns, the junk-science consultant hired by the plaintiff went on 60 Minutes and told the interviewer that a BB from the gun in question traveled as fast as a .22 rimfire bullet. He even chronographed the BB gun and a .22 pistol to compare the results on TV. While the velocity part is true, this expert neglected to inform the interviewer that the difference in energy between a 5.3-grain steel BB and a 40-grain lead bullet makes the bullet about 10 times more powerful. Similar to the difference between being rear-ended by a golf cart or a tractor-trailer going the same speed.

During the Civil War, soldiers were sometimes fascinated that they could see enemy cannonballs bounding along the ground toward them. The speeds at which the balls were traveling were slow compared to rifle bullets, and their great size made them visible. Field commanders warned soldiers that these cannonballs were dangerous; nevertheless, some soldiers did stick out their arms to touch the balls as they bounded past. If they touched one, it usually ripped off their arm at the shoulder, thus imparting a valuable lesson in ballistics and energy transfer to a dying man.

Performance
Pellet performance is different than pellet energy, although the two are always connected. The more powerful a pellet is on target, the more it will do - there's no way around that. But - is it possible for a pellet to do too much of whatever it does? Certainly!

Over penetration
If a pellet penetrates well and the energy level is too high for the target, the pellet may zip through without much effect. Think about a piece of paper being hit by a centerfire rifle bullet traveling 3,000 f.p.s. The bullet goes through the paper with little effect, other than leaving a clean hole. When that same bullet strikes a deer, the effect is thousands of times greater.

It is possible for a pellet to transit the body of an animal without hitting anything vital and exit without imparting a fatal wound - at least not at that moment. That's why we always recommend larger-caliber pellets for hunting. A .22 pellet is more likely than a .177 to hit a vital spot, plus its greater surface area means it has to impart more energy to the target it hits. If you're shooting a powerful .22-caliber deep-penetration pellet, it can also go too far, so you may want to select a pellet that doesn't penetrate as far.

Controlled energy release
This discussion of over-penetration leads us to the world of hollowpoints and wadcutters. Both are great at releasing energy in a target, but neither has a very good record for long-range accuracy. However, the farther you go from the muzzle, the less energy a pellet retains, so the over-penetration problem might take care of itself.

After all the theories have been evaluated, we must remember that only the pellets that hit the target count, so accuracy has to be at the top of every list. But, accuracy can be relative, too. All that matters is that the pellet you select is accurate enough for the job you want it to do at the range you intend using it - not whether it's the most accurate round in a particular airgun.

The bottom line is that accuracy, pellet performance on target, range and caliber all play a part in the airgun question. An airgun hunter who doesn't consider these factors will not be as successful as he could be.