Best Millimeter

So, in going down the rabbit hole about the origins of the frame-mounted decocker on Third Gen Smith autos, I came across this post at Dean Speir's sadly defunct The Gun Zone blog, which is fortunately archived on The Wayback Machine. Apparently the genesis was that the cartridge was decided upon before the gun. Under the direction of John Hall, the FTU had decided that the Bureau was definitely going to the 10mm Auto.

Speir quotes a 1990 Gun Week piece by Mas Ayoob:

"The FTU was given carte blanche to find, or if necessary, create the best possible autoloading pistol for use by FBI agents. Originally, attention had focussed on the 9mm. Expansion of the analysis to include the .45 caliber slowed the process. It was slowed still further when, almost as an afterthought, Hall proposed researching the 10mm as well. When the administration balked, Hall reminded his bosses that a nation was watching them; FBI was a trend setter, and if they adopted a round that turned out to be eclipsed by something else, a disservice would have been done to law enforcement itself as well as to the Bureau."

So the cartridge was decided upon, but that kinda narrowed the pistol choice down a bunch.

Let's hop over to this pistol-forum.com post by (sadly departed) retired Louisiana State Police trooper "LSP972", who was a scholar on such matters:

"Compounding the issue was the fact that The Director Had Spoken; FBI was going to 10mm, despite his FTU people telling him it was a real bad idea; and there were exactly three to choose from... the Colt Delta Elite 1911, the G20, and the S&W. FBI held to the prevailing (at the time) cop perception that any SA gun with a manual safety was bad juju for LE work; one that is still valid today for a general-issue piece. The Glock was still new, and considered by FBI FTU to be the anti-Christ (due to all the negligent injury/wrongful death suits Glock was facing at the time, caused by cops who had not been trained to keep their finger OFF of the trigger, etc.). So that left the S&W.

An amusing aside was the fact that they first approached Sig about making a 10mm P226, and the Sig/USA guys over here said "Sure, we can do that." When the idea was floated in Germany, the Teutonic engineers nixed it, knowing that a complete re-design would be necessary and that an alloy frame would not stand the pounding. What makes it amusing is that , I was told, Sig neglected to inform the FBI of this decision, so after Ted Hollobaugh and his merry men developed the "10mm Lite" cartridge, they informed Sig of this and asked "Where's our gun?"

The answer allegedly was, "Gun? What gun?"

Bottom line, they (FBI FTU) were between a rock and a hard place now, and the S&W offering was the lesser of three evils. The frame-mount decocker was indeed a last-minute add-on. And the rest, as they say, is history..."

The resulting decocker assembly was a kludge. As Chuck Haggard recollects, the decocker lever itself was derisively referred to as the "Bart Simpson" in armorer's classes for reasons that should be obvious. (Trivia: Kansas City, MO issued the Model 4026 as their first autoloader.)

This "Bart Simpson" picture stolen from Midway.