I've been interested to read about the FBI's decision to 'downsize' its duty caliber (i.e. the cartridge fired by the weapons that it issues to its agents) from .40 S&W to 9mm. Parabellum.
The gun blog Loose Rounds has published excerpts from what's described as an internal FBI document summarizing the reasons for the switch. It includes these 'Executive Summary' points.
- Caliber debates have existed in law enforcement for decades
- Most of what is “common knowledge” with ammunition and its effects on the human target are rooted in myth and folklore
- Projectiles are what ultimately wound our adversaries and the projectile needs to be the basis for the discussion on what “caliber” is best
- In all the major law enforcement calibers there exist projectiles which have a high likelihood of failing LEO’s in a shooting incident and there are projectiles which have a high likelihood of succeeding for LEO’s in a shooting incident
- Handgun stopping power is simply a myth [Note from Peter - I agree: that's something I discussed in a previous series of articles]
- The single most important factor in effectively wounding a human target is to have penetration to a scientifically valid depth (FBI uses 12” – 18”)
- LEO’s miss between 70 – 80 percent of the shots fired during a shooting incident
- Contemporary projectiles (since 2007) have dramatically increased the terminal effectiveness of many premium line law enforcement projectiles (emphasis on the 9mm Luger offerings)
- 9mm Luger now offers select projectiles which are, under identical testing conditions, outperforming most of the premium line .40 S&W and .45 Auto projectiles tested by the FBI
- 9mm Luger offers higher magazine capacities, less recoil, lower cost (both in ammunition and wear on the weapons) and higher functional reliability rates (in FBI weapons)
- The majority of FBI shooters are both FASTER in shot strings fired and more ACCURATE with shooting a 9mm Luger vs shooting a .40 S&W (similar sized weapons)
- There is little to no noticeable difference in the wound tracks between premium line law Auto enforcement projectiles from 9mm Luger through the .45 Auto
- Given contemporary bullet construction, LEO’s can field (with proper bullet selection) 9mm Lugers with all of the terminal performance potential of any other law enforcement pistol caliber with none of the disadvantages present with the “larger” calibers
There's much more at the link. Very interesting stuff for gun geeks.