A Little Bit of Ballistics

It’s cold here in the hills. Temperatures have been in the single digits and the wind has been blowing hard. I have a variety of projects I need to be working on but they all involve shooting, and, well, I’m holding out for better days.

This has provided me with some down time and I’ve been looking around on the Internet a good bit. Enough to remind me how little most shooters know about terminal ballistics. If you visit most any shooting forum you will uncover enough misinformation to make you think you’re on the MSNBC website.

In no time at all you’ll learn that you need a 338 Winchester Magnum to kill any whitetail deer north of Pennsylvania, that the 30-30 is so old it will only kill yearling deer – and then only with good hits, and that any cartridge created before 1965 was only introduced to get folks to buy more guns.

I went back through my archives and notes and found some video and information where I conducted a bunch of terminal ballistics testing at the Barnes Bullets laboratory a few years back. I learned a lot of stuff during those experiments and validated some of my opinions.

One opinion I’ve held for sometime deals with comparing the terminal performance of various cartridges. Looking at recovered bullets is the way this is most commonly done. It’s the easy way, but it’s also the way that provides the least information, at least when it comes to information about how the bullet damaged tissue. The best way I’ve found to compare terminal performance is to look inside the dead deer, or whatever animal you’re trying to recover a bullet from. That’s where you find the real story. It’s also where you realize that by looking inside a dead animal, you cannot tell which cartridge killed it.

Here’s an example of Internet ballistics wisdom. Some argue that the 30-06 is superior to the 308 Winchester in every way. Did you know that the 180-grain, 308 Winchester, RNSP CoreLokt bullet will expand wider and penetrate deeper than a 180-grain, 30-06, PSP CoreLokt? Probably not. Most assume the 30-06 will outperform the 308 because it has a slightly higher muzzle velocity. Regardless of these technicalities, I’ll guarantee if you look inside two deer – one shot with each load – you would have no better than a 50% chance of guessing which one killed which deer.

Yes, the middle bullet is obviously a Barnes. But, can you tell which of these bullets created the most internal damage, or was fired from a 30-30 by looking at this photo?

Below you’ll see a list of terminal performance information most often discussed for three loads, all shooting a 150 grain, .30 caliber projectile. The loads were a 150-grain CoreLokt fired from a 30-30 Winchester, a 150-grain CoreLokt fired from a 308 Winchester, and a 150-grain Barnes TTSX fired from a 308 Winchester. Can you match the data with the cartridge?

Load                        Penetration         Expansion                  Recovered Weight

  1.                              19 inches           0.54 inch                    105 grains
  2.                              23 inches          0.53 inch                    124 grains
  3.                              30 inches          0.49 inch                    149 grains

Maybe a better way is to watch the video of the bullets impacting the 10% ordnance gelatin. These videos were shot during the testing I referenced. Now, I’ll tell you up front, the videos might be a bit misleading because of where the bullet stuck the gelatin block in relation to the side of the block the camera was positioned on. I’ll also tell you that its – in most cases – as difficult to guess your wife’s weight to her satisfaction as it is to match gel blocks like these to dead critters.

Regardless of all this scientific stuff, the point is most of what you read on a gun forum – and a lot of what you read in gun magazines – is pure speculation, often based on anomalies, examples of one, and even old wives tales. It’s pontification driven by what has been read and repeated, assumed or found in ballistic charts, and by – yes – looking at recovered bullets. Granted, the 30-30 Winchester is not as powerful as the 308 Winchester. The thing is, the animals don’t know that, especially when they are leaking out both sides. To develop an understanding of terminal performance, stop looking at recovered bullets and look at what the bullet does to the animal.

Finn Aagaard – Possibly the most pragmatic and experienced gun writers of all time.

I’ll leave you with these wonderful bits of wisdom from Finn Aagaard, someone who truly understood terminal performance:

1, One can select figures and dense formulas to bolster about any preconceived notion, and therein lies the major weakness of any of these killing power calculations – they reflect merely the personal opinions and prejudice of their authors.

2, Killing power is a matter of biology, not of math and physics, and is influenced almost totally by shot placement, accompanied by sufficient penetration.

3, Rather than relying on fanciful “killing power” formulas, hunters would do far better to learn field marksmanship and to make some study of animal anatomy, in which subject most of them, including most outdoor writers, are woefully deficient.

4, Given sufficient penetration, what does any additional bullet weight add to killing power? Nothing, absolutely nothing.