FBI Ballistics - why FBI now prefers 9mm
Posted: Tue Jan 13, 2026 3:26 pm
This is a 31 minutes YouTube video with The Firearms Blog in an interview with a 23-year FBI veteran on handgun calibers.
The title is: The FBI Just Settled the 9mm vs .40 vs .45 Debate
Conclusion I got watching the end, is due to projectile technological advances, the 9mm is preferred (135gr or 147gr).
https://www.youtube.com/watch?v=ZybcWWu4ddk
This is the post below the video about it:
I sat down inside the FBI’s Ballistic Research Facility with Scott, a 23-year FBI veteran and career lawman, to talk about the Bureau’s long and sometimes controversial history with handgun calibers. From revolvers to 10mm to .40 S&W, and finally back to 9mm, Scott explains the data, the testing, and the lessons that shaped the FBI’s choices. We cover the Miami Shootout of 1986, the rise and fall of 10mm, why .40 S&W became the standard, and why the FBI ultimately made the decision to return to 9mm. This is the most in-depth, first-hand explanation of the FBI’s caliber decisions ever filmed, straight from the people who test and select the rounds.
CONTENTS:
0:00 Introduction
4:00 FBI Guns & Ammo Before 1986
6:18 1986: The Miami Shootout
8:39 New Gun & Ammo Selection After 1986
11:30 The Rise and Fall of 10mm
14:41 .40 S&W is Adopted
17:17 9mm Replaces .40S&W
22:40 Why 9mm is Better than .40 S&W or .45 ACP
26:55 Conclusion
The title is: The FBI Just Settled the 9mm vs .40 vs .45 Debate
Conclusion I got watching the end, is due to projectile technological advances, the 9mm is preferred (135gr or 147gr).
https://www.youtube.com/watch?v=ZybcWWu4ddk
This is the post below the video about it:
I sat down inside the FBI’s Ballistic Research Facility with Scott, a 23-year FBI veteran and career lawman, to talk about the Bureau’s long and sometimes controversial history with handgun calibers. From revolvers to 10mm to .40 S&W, and finally back to 9mm, Scott explains the data, the testing, and the lessons that shaped the FBI’s choices. We cover the Miami Shootout of 1986, the rise and fall of 10mm, why .40 S&W became the standard, and why the FBI ultimately made the decision to return to 9mm. This is the most in-depth, first-hand explanation of the FBI’s caliber decisions ever filmed, straight from the people who test and select the rounds.
CONTENTS:
0:00 Introduction
4:00 FBI Guns & Ammo Before 1986
6:18 1986: The Miami Shootout
8:39 New Gun & Ammo Selection After 1986
11:30 The Rise and Fall of 10mm
14:41 .40 S&W is Adopted
17:17 9mm Replaces .40S&W
22:40 Why 9mm is Better than .40 S&W or .45 ACP
26:55 Conclusion