The past two months I have been attacked repeatedly by blocks of ballistic gelatin and so far, I have prevailed. My friends find this behavior eccentric. I get huge tubs of ballistic/ordinance gelatin in powdered form from VYSE, and prepare large blocks of material. I shoot these blocks and record the data. If readers walk away from anything valuable in this article, the lesson should be: Try this at home!
Testing bullet performance in gelatin is only one component of cartridge testing, whose ultimate goal is cartridge selection. Most agencies do very little, if any, testing and rely heavily on “standing on the shoulders” method for a decision. This means that they rely on published data for their information. Since a lot of this data may be directly or indirectly sponsored by advertising, agencies should confirm what they are seeing with a little testing of their own.
Cartridge testing usually consists of measuring the velocity of the projectile, the accuracy and consistency downrange, and the measurement of wound cavities created by the bullet. There is a lot of debate about the “real life” application of the results of the testing, but, at the very least, testing allows one to compare the tendency of one cartridge with another.
When I test a particular cartridge, I shoot it at 25 yards from a rest and measure the spread of the bullets on a paper target. Some use a machine rest, which will give consistent results but often takes the characteristics and mechanics of the human structure that guides the equipment out of the equation. There are cartridge/handgun combinations that are consistently better, but generally 4 inches or less in displacement on a target at 25 yards should be considered adequate for law enforcement purposes. The question is, “How many target groups must one fire before one can be satisfied with the accuracy of a cartridge?”
There isn’t a definite answer, but I like to go through a couple boxes of cartridges before I am satisfied. Bear in mind that accuracy is a single gun/cartridge comparison, so the best we can do is predict the trend of a cartridge against the trend of the handgun. For example, I used a Glock 22 to test 40 S&W and .357 SIG cartridges (using a Lone Wolf Distributors barrel). It is safe to say that my results would be similar to most other users using a Glock 22, simply because of consistency in manufacture. This, by the way, is a very good reason to own a Glock. I measure the velocity of a bullet, using an Oehler Model 35 Proof Chronograph. This model is perfect for testing because one simply has to set the chronograph up and fire through the screens. The product does all of the tabulating and calculations for the user automatically. I get a printout which includes individual velocity, average velocity and standard deviation. This is beyond my math capabilities and I appreciate Oehler Research Inc. for this.
The FBI Test Protocol for law enforcement cartridges actually includes nine different terminal performance events: bare gelatin, clothing, steel, wallboard, plywood and automobile glass. The clothing and glass tests, originally conducted at 10 feet, are duplicated at 20 feet.
The FBI Protocol, and any other bullet testing, is subject to considerable debate. Ideally, the bullet that performs under the broad spectrum of media in terminal ballistic tests is the best choice for law enforcement use, correct? Maybe. Some argue with catchphrases like “stopping power”, “temporary cavity” and “one shot stops.” Others suggest that FBI testing protocol does not really square up with reality. Some offer “more scientific” tests, which include using by-products from butcher shops and similar testing media. The most interesting arguments are the anecdotal ones. They come from examples of single shooting incidents that support (or purport) the efficacy of a particular cartridge.