The FBI and the 10mm

Overview

Due at least in part to a shoot-out between FBI agents and two felons in Florida in the mid '80s the FBI decided to review the effectiveness of the 9mm rounds that their agents were carrying. They did a full review of not only the 9mm but also the .38 Special, .45ACP and the 10mm. Their findings were that the 10mm was superior to all of the other cartridges tested.

The first disclaimer here is that the 10mm full power load is far more than most of their agents were willing to use. They then devised a reduced power 10mm load that is the performance equal to what we now call a .40S&W. The second item is that the "FBI 10mm" (.40S&W) is only "marginally better" (their exact words) than the .45ACP.

With the above in mind, here are selected portions (selection based on direct relationship to performance of the rounds specified) that provide insight for us to understand that there is NO ultimate self defense round. Merely some that are "at the top of the list". Keep in mind that there are newer rounds available now that were not in existance when these tests were run.

This information is from FirearmsTactical.com and the PDF "FBI 10mm Notes" written by SSA Urey W. Patrick, Firearms Training Unit, FBI Academy, Quantico, VA.

Reasons for Adoption of 10mm

1. Initial Test Results (12/88-1/89) on which decision based:
   1. .38 Special +P - 158-gr lead hollow point
      • Success rate meeting 12" minimum: 67.5%
      • Wound volume (cubic inches of tissue disrupted) 2.16
      • Average penetration: 11.76
      • Test barrel average group: 2.992
      • Service weapon average group: 10.863
   2. 9mm Subsonic - 147-gr jacketed hollow point
          [NOTE: This is the 9mm round the FBI found to be most effective]
      • Success rate meeting 12" minimum: 67.5%
      • Wound volume (cubic inches of tissue disrupted) 2.82
      • Average penetration: 13.84
      • Test barrel average group: 2.305
      • Service weapon average group: 2.774
   3. .45 ACP - 185-gr jacketed hollow point
      • Success rate meeting 12" minimum: 92.5%
      • Wound volume (cubic inches of tissue disrupted) 3.98
      • Average penetration: 19.95
      • Test barrel average group: 2.040
      • Service weapon average group: 4.319
   4. 10mm FBI Load - 180-gr jacketed hollow point [980fps]
      • Success rate meeting 12" minimum: 97.5%
      • Wound volume (cubic inches of tissue disrupted) 4.11
      • Average penetration: 17.90
      • Test barrel average group: 0.893
      • Service weapon average group: 2.550

2. Common Questions
   • Since the .45 tested so well, why not adopt it instead of a new gun/caliber?
     • First, the [FBI] 10mm tested better, albeit marginally better, than the .45 and we were committed to adopt the best round. Nonetheless the [FBI] 10mm has far superior accuracy, allows for slightly higher capacity than similar sized .45 weapons, is a new cartridge with room for further improvements whereas the .45 has been around for 80 years and is as good as it is ever going to be, and the recoil of the [FBI] 10mm is softer than that of comparably sized .45.
     • Second ...... (relates to selection of a new weapon)
     • Third, the difference between the two is marginal and had the Director said "go with the .45", we would have done so gladly. However, based on the results of the testing, we would not recommend the 9mm for adoption as the FBI issued round.

   • Since you developed the 10mm, why not do the same thing with the 9mm?
     • The 9mm has been in existence since 1902. It is actually an older cartridge than the .45. In that time, so many variations and designs have been tried that it is hard to imagine anything new that could be attempted. (goes on to site specifics)

   • Aren't you afraid of over penetration?
     • The fear of over-penetration is a misconception, which was created back when law enforcement was trying to overcome misinformed public resistance to the use of hollow point ammunition. In the process, we began to believe it ourselves. First, our lawyers are unaware of any successful legal action from injury of a bystander due to a round over-penetrating the subject. We are aware of numerous instances of Agents/officers being killed because their round did not penetrate enough (Grogan and Dove, for example). Further, if you examine shooting statistics you will see that officers hit the subject somewhere around 20-30% of the time. Thus 70-80% of the shots fired never hit their intended target, and nobody worries about them - only the ones that "might" over-penetrate the bad guy. Third, as our testing shows, even the most frangible bullets designed specifically for shallow penetration will plug up when striking wood or wallboard and then penetrate like full metal jacketed ammunition. We are aware of successful legal actions where an innocent party has been struck by a shot passing through a wall, but as we have proven, ALL of them will do that.

   • Eight questions skipped, not relating to this paper.
   • Why didn't the 9mm do better - that is surprising?
   • The 9mm is no more effective than the .38 Special, which should not be surprising since they are the same caliber bullets (.35 caliber) at the same range of velocities and bullet weights.
   • Are you saying the 9mm is no good?
     • No. We are saying it is as good as a .38 Special, which has served us for a long time. It has severe limitations, which we are not willing to accept. It is woefully inadequate for shooting at people in cars, for example, and over half of our shootings involve vehicles. It is a marginally adequate wounding agent. We have a number of 9mm shootings over the past couple of years, and if you define a good shooting as one in which the subject stops whatever he was doing when he gets shot, we have yet to have a good one, and we are hitting our adversaries multiple times. We have shot half a dozen dogs in the past year and have not killed one yet, although we have run up a significant veterinary bill. The 9mm with proper ammunition is not a bad round. It is just nowhere near as effective as the 10mm and .45 offerings, and the disparity between it and the larger calibers has remained a constant throughout all the testing we have done over the past two years.

   • Four questions skipped, not relating to this paper.
   • What is the best round in?:
     • 9mm - the Federal 147 grain HydraShok
     • .45 - the Federal 230 grain HydraShok
     • 10mm - the FBI load, a 180 grain Sierra bullet at 980 fps
     • .380 - there isn't one. The full metal jacketed round is the best of a bad choice,
           but only because it might penetrate
     • .357 - we haven't found one that is sufficiently better than a .38 load to justify all the sound and fury of shooting it, unless you need the increased effective range, which the higher velocity gives you. We have only tested five so far, and none of them stand out.
     • .38 Special - the Federal 147 grain HydraShok

   • Remainder of the questions omitted because they do not relate to this paper.

   Observation

   Shot placement is obviously critical, and our test criteria presume that the shot is placed in the vital area of the body, which contains the brain, upper spinal cord, heart, and aorta/vena cava. this area runs from just above the eyes to the diaphragm, and is about 4 inches wide. But as our experience in Miami amply illustrates, shot placement is only the first part of the equation. Jerry Dove placed his shot perfectly. Bullet performance is critical to translate shot placement into an effective incapacitation wound. If shot placement was all that mattered, we would arm all Agents with .22's. Secondly, perfect shot placement may be difficult to attain in the stress and dynamics of a shooting incident. The larger calibers offer a "margin of error" in that where a smaller bullet may just miss the aorta, for example, the larger one in the same placement will damage it. A good example is killing a 400 pound pig with a .22, something commonly done on the farm. If the shot placement is exactly right, the pig is instantly killed. If it is off less that an inch, the pig goes wild and the process of killing becomes rather lengthy and involved, whereas a larger caliber would succeed with a larger margin of miss than an inch. (Larger calibers are not used because they ruin too much meat of the pig - a consideration that does not come into play in a shooting incident - and besides which, nobody is going to die if the pig is not instantly killed anyway. In shootings, just the opposite is true).

   
   
   
   

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