In preparation for Karl Rehn's Historical Handgun Class I've been reading about the motivations and practical consequences of transitions from double-action revolvers to double-action/single-action pistols. I have no personal memory of this, being too young, and only becoming involved in handgunning in the early 2000s, when polymer, striker-fired pistols were already commonplace. It took a long time for the industry to transition away from double-action revolvers and single-action pistols to occur. In some places, the transition never occurred, like Miami PD, which delayed any transition, then skipped over the DA/SA and into striker fired pistols. In other places, the DA/SA lives on: as in the US adoption of the Beretta 92FS or the resurgence of DA/SA pistols like the Beretta and CZ-75-derived pistols among competitive handgunners.

The early history of Smith & Wesson pistols is explained:

The original 9mm Smith & Wesson was officially introduced in 1955 though it did not garner any police or military contracts at this time. ... In 1957, the 9mm pistol became the Model 39 as Smith & Wesson moved to a new numbered system. Smith & Wesson M 39, R. K. Campbell, Small Arms Review

Early Adoption of the Model 39

Although the Illinois State Police (ISP) were not the first law enforcement agency to adopt the Model 39 or a DA/SA pistol, they were, as Massad Ayoob puts it, "the ripple that turned into a wave". He has written about the ISP's motivation and adoption several times.

In 1967, the ISP became the first large department in the United States to adopt a semi-automatic pistol as a standard-issue service sidearm, the 9mm Smith & Wesson Model 39. Many people do not realize that this decision came largely from the fact that Sgt. Louis Seman, then head of the ordnance section of the ISP, had noted that troopers’ shooting skills in qualifications were dismally lower with the 2-inch-barreled .38 revolvers (then standard for plainclothes and off-duty) than with longer-barreled service revolvers. When the Model 39 was adopted and made the only authorized gun for troopers for off-duty and plainclothes carry, average qualification scores actually increased overall. - Carry the Most Gun Possible by Massad Ayoob, Tactical Life, Jan. 1, 2013

There was a time when the Illinois State Police encouraged its troopers to use their issue weapons as much as possible. The S&W Model 39 they began issuing in 1967 was expressly adopted to have a single handgun suitable for uniform wear, plainclothes assignments and off-duty carry. It worked out reasonably well. - Firearms Commonality by Massad Ayoob, American Handgunner

Safety vs. Capability

I did some dry practice with a S&W 5906, a double-stack, steel framed, third generation descendant of the Model 39. I started with a double-action trigger pull with the safety off. My naive assumption of drop-safety due to its ubiquity in modern handguns led me to believe that the Model 39 meant that early-adopters were getting a great compromise between the 1911 and revolvers (that is, trading a manual safety lever for a double-action trigger pull prior to the first shot). In fact, in order to maintain a modern standard of safety, they had the worst of both worlds:

  1. the drawstroke and presentation required that the safety be disengaged
  2. the initial shot required a long, heavy, revolver-like double-action trigger pull

This was corroborated by another history of the Model 39.

Still, the weapon had to be carried on-safe due to the lack of a firing pin safety. - Smith and Wesson Model 39..., author unknown,, Dec. 20, 2015

I hadn't seen any pictures of ambidextrous safeties on early Model 39s or 59s, so I wasn't sure how this was managed by left handed shooters. There must have been some left-handed Illinois State Police officers required to carry the 39 on- and off-duty. I found this description of a solution:

At the time of the Model 39's introduction, two of the most influential handgun experts in the USA were Col. Charles Askins, Jr. and Major George C. Nonte, both Army men. Each took the Model 39 as a personal favorite. Charlie carried his often. A southpaw, he wore it with the hammer down on a live round and the safety off, since it's [sic] safety decock lever did not then come in an ambidextrous form. - Greatest Handguns of the World by Massad Ayoob, pp 274-275

In terms of usability, this is a major improvement. In terms of safety, it's a downgrade from a modern perspective. I'm still trying to confirm this, but I think that, in 1955, a firing pin safety for pistols was still under patent protection from 1938. Drop-safety had become common in double-action revolvers since the Iver Johnson Safety Automatic in 1896. This explains one aspect of the attitude toward pistols as inherently more dangerous than revolvers (with respect to unintentional damage or injury).

Returning to to my initial conundrum as a lefty, I think the conclusion is that most who carried pistols instead of revolvers in the 1960's were likely already trading away some safety for some capability. The Model 39, for a right-handed shooter, coming from a revolver, struck this compromise:

  1. positive - short, light following trigger presses
  2. positive - greater capacity (8 vs. 6)
  3. positive - simplified reload procedure
  4. neutral - long, heavy first trigger press
  5. negative/positive - more complex presentation (manual safety)

You may argue that the presentation isn't much more complicated, but I'll let you argue it with Massad Ayoob, who has written in Greatest Handguns of the World and Combat Handgunnery about "saves" that occurred when guns taken from police officers could not be immediately used to shoot the officer by their assailants. It may not be much more complex with familiarity, but that's not the same as "simple".

Police and civilians have different concerns. For a civilian, the added complexity of disengaging a safety lever may be a hurdle for a spouse, partner, or older responsible child who shoots very infrequently, but still relies on the pistol for home defense. On the other hand, police officers are obligated to develop a familiarity with their equipment and Ayoob's descriptions provide evidence that ISP officers were, as he has no examples of officers injured or killed because they failed to disengage the safety.


A great deal of Smith & Wesson's knowledge about the Model 39 came from the officers and armorers of the Illinois State Police, who tuned their guns to run reliably despite limitations of the "no-dash" Model 39s.

S&W made some changes to the extractor and magazines and around 1978 designated the guns 39-2 and 59-2. In 1980 S&W added a more robust rear sight, a firing pin safety, and changes to the feed ramps. They designated the pistols 439 and 459 respectively. - Smith and Wesson Model 39..., author unknown,, Dec. 20, 2015

Smith and Wesson remedied the lack of drop-safety in (approximately) 1982 with the introduction of the second-generation 439, 539, and 639. Those and all the third generation, four-digit models (e.g., 5906) are drop-safe.


Leaving aside more subjective matters such as grip angle and contours, in terms of length-of-pull, the Model 39 isn't much of a change relative to either the 1911 or medium frame revolvers. I measured all three in the neighborhood of 70 mm linearly from backstrap to trigger (give or take a couple millimeters depending on 1911 trigger). This isn't the whole story, as the actual grip circumference plays a role. I think it's worth mentioning, though, because like all DA/SA pistols, it's tempting for users with smaller hands to consider only the length of pull in single action mode because that's how the guy at the gun store hands it to you, and how you might shoot it at the range unless you think carefully. In fact, you'll probably end up with your finger touching the trigger as you would a double-action revolver (i.e., with the middle of the trigger straddling the distal joint) rather than as you would a 1911 (i.e., with the middle of the trigger touching the middle of the distal "pad"). This finger-trigger interface means that you really need a shorter length of pull than you would otherwise, and this same evaluation applies to all DA/SA pistols.

"More Firepower"

On paper, nine rounds of 9mm looks like an upgrade from six of .38 Special, but the reality is a little more complicated.

First, for both feeding reliability and social reasons, the Model 39 was adopted by the ISP with full metal jacket (FMJ) ammunition, although jacketed hollow point pistol ammunition that offered enough of an advantage over FMJ to be attractive was starting to become available, starting with Super Vel in about 1969, and followed closely by Speer, Hornady, and others. This progress initiated a technological tug-of-war at the gun-ammunition interface. In an era before SAAMI +P rated ammo and guns, the revised feed ramp into an unsupported chamber of the Model 39 and 59 combined with high pressure loads like the Super Vel 90 gr. 9mm load to create occasional "kaboom" incidents long before the modern era of Glock .40 S&W "KBs".

Second, the magazines of early Model 39s could only be reliably loaded with eight cartridges (including one in the chamber).

The 39 was originally designed with an 8-round magazine, with a ninth cartridge to be carried in the chamber. ISP ran tons of ammo through those guns, and discovered when loaded all the way up, there was potential for misfeed. The policy recommended was to load only seven rounds per magazine, which helped to cure the problem and became 7+1-for-sure beat 8+1 rounds maybe. - Reliability vs Round Count by Massad Ayoob, Daily Caller, Oct. 21, 2015

The former consideration, less effective ammunition than the readily available Elmer Keith-style semi-wadcutter or perhaps even lead round nosed projectiles for .38 Special and .357 Magnum, is the more acute in my opinion.