9mm vs. 40 – Is the .40 Caliber a Better Handgun Cartridge?

In the article, Scott Wagner, a retired law enforcement officer and current trainer, delves into the long-standing debate between the 9mm and .40 caliber cartridges. The discussion starts with the origin of the .40 caliber, which was developed primarily for law enforcement use in response to the need for more stopping power. Wagner explores the historical context, emphasizing the significance of the 1986 FBI Miami Shootout, a pivotal event that highlighted the deficiencies of the 9mm round in critical situations. This incident led the FBI to initially adopt the 10mm Auto before transitioning to the .40 caliber for its balance of power and manageability.

Wagner's examination continues with a comparative analysis of the ballistics and real-world performance of both rounds. He discusses how technological advancements in ammunition design have narrowed the performance gap, making modern 9mm rounds nearly as effective as the .40. Despite this, his own testing and evaluation using modeling clay demonstrate that the .40 caliber still delivers superior stopping power due to its larger diameter and greater mass. He details the results of his tests with both the Springfield Armory Garrison in 9mm and Springfield XD Tactical in .40, showcasing the differences in penetration and expansion.

The article concludes by reflecting on the current trends and preferences in law enforcement and civilian use, noting the FBI's switch back to the 9mm due to its ease of handling and advancements in ammunition technology. Wagner emphasizes that the choice between 9mm and .40 ultimately depends on personal preference, the shooter's ability to handle recoil, and the intended use of the firearm. For a deeper dive into this comparison, read the original article titled 9mm vs. 40 – Is the .40 Caliber a Better Handgun Cartridge? - The Armory Life.