A review of the literature reveals a wide range of test media and methods. Even the use of variable-controlled gelatin, which has an excellent correlation to human tissue, is opposed by those who use only the size of the temporary stretch cavity in their theory of stopping power. In reality, the only way to test the effectiveness of police duty weapons is to collect actual shooting results from the street which requires a painstaking attention to detail in gathering the data. A study on this subject, due to be released in January 1992, used information gathered from officers' and medical examiners' reports, X-rays, morgue photographs, and in some cases, the recovered bullets. At least one dozen shootings with ammunition of the same make, weight, and style, and fired from the same barrel length, were needed to constitute a "result" for the database. The forthcoming book covers 10 calibers from the .32 auto backup gun to the .45 Colt big bore cannon; this article discusses the most effective, moderately effective, and least effective loads for the .38 Special +P, .357 Magnum, 9 mm, and .45 automatic weapons.