The Kind & Knox gelatin blocks measure 8x6x16 inches and cost nearly $30 each. The gelatin can't predict what a bullet will do when it strikes metal or glass in a street fight, or bone in a hunting animal, but it shows ideally how much the bullet will expand and how much weight it will retain.

I'll also list the average instrumental energy for a round, and if measuring velocity at the target, I'll also give the energy at the target. Energy is a function of bullet weight and velocity and is expressed by velocity squared times bullet weight (in grains), divided by 218,225, divided by two. Square the velocity, multiply it by the bullet weight, and divide by 436,450. Once in a while I like to give the power factor for a round, and this is a function of bullet weight times velocity, divided by 1,000.

Hunting rounds also get a number called the Taylor Index. Concocted by famed African hunter John Taylor, this index refers to the way a cartridge performs in the field on big game. This number is calculated by multiplying the bullet's caliber by its weight times the velocity and dividing the resulting number by 7,000 (grains to the pound, in case you're wondering). Taylor had things about right, and I often find that his formula explains well why the .454 Casull seems to be more lethal in the field than are many high-powered rifles (at handgun ranges, of course).

The way a bullet flies through the air is great stuff, to be sure. It's always nice to see a round go exactly where it's directed, and it takes a good bullet to do that. Seldom, however, is that the only measure of bullet performance, unless I'm only shooting at paper. If I'm paper punching, I concern myself with accuracy, ability to function and cost. An accurate, cheap load that works gets the nod--if there's such a thing. In this line of work, I tend to think that the true measure of a round consists of a mix that includes accuracy, velocity and the power that results from it plus adequate penetration.

I strongly feel that the mix should also include the way a bullet performs in a medium that approximates what you'd encounter on the street as well as in the field. I got started handgun hunting quite some time ago. Early in my hunting career the .30 and .357 Herrett were accounting for some spectacular results in the field. Had sheer energy and potential accuracy been the only important factor, they were winners, regardless of the chosen bullet. Once in a while, however, things didn't work out quite so well when bullets that were designed to work well at 1,000 fps or less were hitting game at very nearly twice that velocity in some cases. I once saw a whitetail buck take a hit from a friend's .357 Herrett at less than 50 yards and go down like a stone, only to jump up and escape onto ground we couldn't hunt because the bullet detonated on the shoulder and didn't make the boiler room! The wound was massive and shallow.

Predicting how a bullet will perform in the real world is risky business. There are too many variables that enter the equation. Throw in heavy clothing, metal or glass on the street, or a twig in the field and all bets are off. Still, it is possible to compare loads by blasting away at carefully prepared ballistic gelatin blocks at a known and uniform range. If nothing else, I'll end up with a relative measure of past bullet performance in ballistic gelatin.

I rely on 8x6x16-inch blocks of gelatin prepared from Kind & Knox powder. Ideally, the mixture is 10 percent gelatin, 90 percent water that is blasted when it is exactly 39.2 degrees F (4 Centigrade). I've found that if I need a slightly higher percentage of gelatin, I carefully measure nine liters of my hottest (140 degrees F) tap water into a clean, white plastic bucket and slowly add 1,100 grams of gelatin powder to the water while using a plastic paint mixer on a power 3/8-inch drill to mix things. My wife, Cindy, slowly adds the powder while I run the mixer.

The author's calibration procedure calls for a .177 BB to penetrate gelatin when launched at 590 fps. Johnston uses a Daisy Model 880 that shoots within 7 fps consistently on the third shot.

I pour the hot, liquid mixture into custom aluminum molds made from .032-inch sheet aluminum. The clean molds are coated with a thin coating of PAM non-stick oil before they are filled with the mixture. When the mold has been filled, it is set aside where it cannot be contaminated for 4-5 hours and cooled to room temperature. This allows the air that was captured in the mixing to escape. It's impossible to mix things thoroughly without introducing air bubbles, but it helps to add a couple of drops of concentrated cinnamon oil to the hot water before mixing.

Then the molds are transferred to the refrigerator in the farm shop. (Ballistic gelatin spoils rapidly at room temperature.) I have yet to see an affordable refrigerator that will hold exactly 39.2 degrees, nor have I found a way to hold a block uniformly at 39.2 degrees. The acceptable measure of a properly mixed and calibrated block of gelatin calls for a .177-caliber ground steel BB to penetrate 3.34 inches (8.5 cm) when launched at 590 fps. I've found that my Daisy 880 will launch the third BB from a string at 590 fps or so within a couple fps with seven pumps and that it'll routinely get very close to the required depth when I use the 11 percent mixture. I use a dial caliper to measure the penetration of the BB and try to launch the shot "for record" within seconds of the shot from the Daisy air rifle, assuming that the Daisy hit the mark. The gelatin can't be shot until it's cooled for at least 48 hours, and I don't let it sit for longer than five days or so before it's blasted.

It would be great to be able to run the shots through twigs, wallboard, glass and metal and then into a bunch of blocks of gelatin. Unfortunately, I end up getting about 10 blocks of gelatin from $280 worth of Kind & Knox powder, and we get one shot per block unless a bullet penetrates less than 8 inches. It's not within reach of the average writer to blast merrily away at dozens of $30 targets for an article. That would be a direct line to the poor house to be sure, while the time invested would likewise be unmanageable, to boot.

Be that as it may, when the smoke has cleared, I end up knowing how this lot of ammunition performed on paper, what ballistics it generated and how it performed, relatively speaking, in ballistic gelatin. While I can't accurately predict exactly how it may work in a specific situation, I do my level best to come up with a yardstick that you can take to the bank.

I hope you've enjoyed learning how I do our thing out here in the boondocks and that the next time you see my work here, you'll have some measure of the effort that goes into each piece. I still encounter locals who don't think a writer really works. Granted, it's fun, but it's work just the same.