.45 Colt ammo from two revolver makes with different twist rates and barrel lengths. Although velocities and muzzle energies from the shorter barrel were less, the slower twist let the bullet start to tumble in the gelatin and increased the wound-cavity volume by a modest but statistically significant amount. See the accompanying chart on the next page.

Sometime in the early 1980s, our lab’s caseload became so oppressive that we didn’t have time to continue the ammo-test program on a regular basis. Any testing was at night or on weekends, slowing the program. After I left the lab in 1987, our section chief decided that the new FBI ammo test protocol was becoming the de facto standard, and all testing in Dallas ceased.

The FBI tests focused on the size of the permanent wound cavity and total depth of penetration in long gelatin blocks; ours determined the size of the temporary cavity and how it was distributed in short blocks. Were these two systems mutually exclusive? Not at all. Years later, I obtained the early FBI test results and compared them to the Dallas results where the same loads were tested. Most of the loads that the FBI found to have good performance also tested well on our system.

When I traveled to present our program results to various police academies around the Southwest, some recruit invariably asked what I chose for personal protection after testing hundreds of loads. The answer was consistent: a custom Colt Government Model 1911 with Speer’s old 200-grain “Flying Ashcan” hollowpoint. I never had to use it in anger but was always confident that a solid evaluation program supported my decision should a situation “go bad.”

I started this column by saying we recommended the right cartridge for the wrong reason. Our recommendation of the specific .38 Spl. LHP loading was based solely on cavity volume. As we later discovered through more detailed testing, the cartridge also produced optimum wound cavity distribution. The Dallas PD stuck with the LHP until issuing 9mm Luger sidearms in about 1989.

From all of this, I learned two unavoidable facts: First, there’s no such thing as a “magic bullet.” Even the mightiest gun/cartridge combos had the rare failure to stop. Even more basic was the second fact: A center hit with a .38 roundnose always outperforms a miss with a .44 Mag.