In 1994, the FBI adopted a new model of the H&K, the MP5/10A2, in 10 mm Auto. It used the same “10 mm light” load as the Smith & Wesson Model 1076 pistol as the gun was not designed for the full-power 10 mm round. This model has since been pretty well removed from the field, and the AR family—M16s and M4s—have replaced it as an entry weapon. This changeover to Gene Stoner’s baby didn’t come easily. As mentioned previously, it was thought that the 5.56x45 mm NATO had too much range and penetration for urban use. It took a lot of testing to convince the powers that be otherwise.

Special Agent Bob Taubert, then assigned to the unit responsible for training the FBI’s field SWAT teams, pushed for the change. When I talked with him recently, he gave full credit for the initial push to two Southwestern law officers, cousins Jack and Rick Furr. They, in turn, give credit to Clint Smith of Thunder Ranch fame, who was an early proponent of the AR as an entry weapon. Taubert finally convinced the Firearms Training Unit to test the ballistic performance of the .223 Rem. against the two SMG rounds then in use, the 9 mm Luger 147-gr. JHP and the 10 mm 180-gr. JHP.

Ballistic Research Facility personnel ran the rounds through the complete FBI protocol. When the smoke cleared, it was apparent that the .223 Rem. rounds penetrated less than the handgun cartridges. Except for the longer range of a missed round, the AR system was found to be a safer and more effective round to use in close-quarter combat.

The switch from submachine guns to the M16 and M4 was then rapid and complete. The MP5 in both calibers was replaced both in training and in the field. Today, new agents in training at Quantico use M4s with “iron” sights and modified to fire semi-automatic only. In the field, investigative agents use an M4 made by Rock River Arms with an adjustable-length stock, EOTech sight on a Dominator mount with a SureFire M73 light. The rifles are semi-automatic only. The field SWAT teams are using mostly Colt M4s capable of both semi- and full-automatic fire with PLR1 lights by Streamlight. A very few MP5s in either 9 mm or 10 mm are still out there but are seldom put into operation, and new agents in training at the FBI Academy, Quantico, are no longer trained on the system.

The Bureau often follows technical developments of the military, even more so in its SWAT teams. It will be interesting to witness their changes in arms in the future.

Note: The author is a retired 31-year law-enforcement veteran with more than 20 years with the FBI. He spent more than half of that time as an instructor at the FBI Academy at Quantico, Va., teaching firearms, arrest techniques and street survival. His opinions in this article are not necessarily those of the FBI.

Photo courtesy of the Federal Bureau of Investigation