Left side of HK USP45 Compact for illustrative purposes. At the dawn of the autoloading era revolvers were mainstream and simple enough: double-action/single-action for any with more sophisticated needs or single-action only (cock first to fire) for everyone else. Safety was one's own trigger finger and this philosophy was the first to carry into autoloaders along with newer calibers made to emulate performance of their rimmed counterparts. John Browning invented the reciprocating slide while concurrently there were different external safeties evaluated on a few Mauser and Luger models. Today there are a small host of handgun operating systems and today's post will evaluate the major ones.
Philosophy
First to be acknowledged are the differing schools of thought, specifically to pistols available to civilians. Rifle operating systems are as diverse as their families and derivatives (bolt-action, Garand, CETME/HK, etc.) and may be covered later though it's worth noting a growing number of First World militaries seem to be consolidating around the Stoner manual of arms. This is not in terms of how the weapon functions (with few exceptions full-size service handguns today use some variant of Browning recoil operation) but in their end-user handling.
There are two major differing points of view, both with merit: 1) particular to those community defense-minded is the idea that training in a variety of styles is important so there can be familiarity with handling any "pick up" weapon in emergencies; 2) particular to those individual and family-defense minded is the idea to pick one style and stick with mastering it to preempt any potential hang-ups. In most but not all cases those of the second school of thought will have multiple handguns with identical or near-identical manuals of arms often of the same make (i.e. Glock) or family (i.e. 1911). As I consider myself part of the militia that is a community defense orientation so I deliberately invest in variety, but as with other issues that provoke the internet trolls I reserve no judgment for those who think differently so long as I can see it both ways.
The following list is not meant to be comprehensive but reflect what is generally available today. I chose to present them in (near as I could determine) their order of invention rather than my own arbitrary views on how they derived from each other. I am conscious in not recommending any one over the other and speaking from my own experience; defense choices are individual and what is advisable is handling (and whenever possible, shooting) before buying.
Browning (Single-Action Only with Manual Safety)
There are actually at least 3 handling styles in Browning-developed pistols: no external safety (adapted to the Soviet Tokarev), quasi double-action via a hammer hidden or internal (the first Colt officer compacts), and manual slide safety standardized by the M1911 and Hi-Power. Their commonality is single-action operation like that of common revolvers of the time, though what is most prolific today is the last of these due to 1) the first being usually foreign-produced and US import regulations require addition of some external safety and 2) demand for the second has evaporated since striker actions offer nearly the same performance for better value. So for purposes of this post Browning-style is a single-action only capable of safe Condition 1 (cocked and locked) carry.
Hands-down the most popular platform of this style is the 1911, invented by Browning but taken in many directions over the past century (including a few double-action variants started first by Colt). There has also remained a strong enough niche for the Hi-Power that updated versions have been introduced this past year. While often associated with old-school types this style continues being a favorite that refuses to be displaced, its top asset being operational consistency all the way down to the trigger pull. Striker-fired, which offers similar consistency, is the new military standard but many will continue to argue for how single-action generally offers a lighter pull weight and reset.
Walther (Single-Action/Double-Action with Manual Safety/De-cocker)
Carl Walther developed this style way back in 1929 for the PP series but it "went mainstream" with the P38 which became one of the unofficial NATO standard pistols (judged by commonality of member state adoption; the one other was Browning's Hi-Power). Today the PPK(/S) family continues its undying market appeal but is now the only example of a native Walther platform still using this manual of arms. On the service pistol side of things there is another gunmaker at least as famous that also endures in markets despite facing mass military phasing-out within the past decade: Beretta. The Model 92 family, one of which was the US armed forces' M9 for over 3 decades, was a well-deserved winner by combining large capacity like the Hi-Power with 9x19mm-centric (already NATO standard pistol caliber) reliability by integrating the open slide of Beretta trademark with the open chamber of Walther's P38 family.
Along with Walther's operational architecture Beretta implemented the standard Walther safety system: a manual switch that upon flipping to safe concurrently de-cocks the hammer if pulled for single-action operation. Like Browning-style single-action trends nice and light with great follow-up, but at the same time opposite in that cocked and locked carry is impossible due to the integrated de-cocking. It should be emphasized (and some procedural manuals dictated one way or another) that the double-action pull is so heavy it can be considered almost a safety in itself, a philosophy others made their primary manual of arms.
However in the 21st century Walther-style has become less-common so this would pertain only to those who happen to be looking at a specific pistol which happens to use this system. The PPK/S is the only subcompact of note still being produced while Beretta 92 variants cover the full-size and compact realm: that's pretty much it except for secondhand historical weapons (P38s, Makarovs) using the same. As one who already has a PPK/S I could transition to a Beretta well enough, but for those who wish not to there is an alternative: the 92G variants feature a safety that does not lock, rendering it a de-cocker only.
SIG Sauer (Single-Action/Double-Action with De-cocker)
The BDA .45 was a US market variant of the West German-made P220 sold under the Browning brand with "SIG-Sauer System" displayed prominently on the slide; the whole line was a unique amalgamation of the premier styles of the time, the .380 ACP a Beretta Cheetah modified with full-coverage slide while the 9x19mm was one of the rare double-action Hi-Power models.
1975 must go down in history as the turning point into the modern pistol era: that one year saw design of the Beretta 92, finalization of the CZ 75, and the Swiss replacing their accurate but complex SIG P210 with the simpler SIG Sauer P220 (produced in Germany to manage costs). Derivates of two of these (not the CZ 75 since it was a product of Warsaw Pact Czechoslovakia) would compete in the finals of the XM9 trials selecting the US military's new standard handgun for all branches, the results close enough that the argument still gets made SIG Sauer's P226 was the real winner while Beretta came on top through unfair political connections and/or underbidding (testimonies differ depending on who's asked). Regardless, SIG is enjoying the last laugh today as their P320 now serves as the M17 and M18 modular replacements of the M9.
The P226 still proved superb enough to be adopted by the Navy SEALS with its compact P228 & P229 plus subcompact P239 siblings likewise picked up by numerous US federal agencies and special military units. Until the 21st century when US-based SIGARMS diversified the line with their take on the 1911 and single-action only variants of their standard models originally targeting the competition market, the SIG Sauer system meant only one distinct thing: safe to be carried double-action ready with no external safety, not dissimilar to one of the two options of the Walther system except SIG's de-cocking lever is a prominent frame-mounted sliding switch that can be easily manipulated with the grip thumb. SIG Sauer has also earned a reputation for its superb trigger system relative to most others' factory defaults.
Unless specifically single-action only (thus using the Browning rather than SIG Sauer manual of arms due to the addition of a manual safety) all hammer-fired SIGs use the SIG Sauer system. Others offer similar operation via a de-cocking lever either by itself or as an option among others but only SIG features the trademark large frame-mounted de-cocker, leaving others to integrate de-cocking function on a manual safety switch which could function either Walther-style or others described below like Browning-style but with addition of a double-action option. Today even SIG models made for the military are Glock-style striker-fired, but their traditional hammer models with de-cocker remain a widely-available favorite.
CZ/Koucky (Single-Action/Double-Action with Manual Safety)
Socialism having a well-earned reputation for stifling innovation it is a notable occasion when a breakthrough is made by the Second World; the CZ 75 family is one of these. In appearance and function the original CZ 75 is like a double-action Hi-Power, but its specifics have more in common with the Petter design that produced the French M1935A and SIG P210. The Koucky brothers were actually the first to introduce a double-action option to the Browning system.
The CZ 75 family is a story worth its own blog post (several are out there for those interested), but in the 1980s FN and Browning itself would produce double-action Hi-Powers that worked on somewhat similar principles. The US-made Browning BDM and Belgian FN HP-DA took their own approaches which swung more towards Walther- or SIG-style in favoring a double-action first shot while others making CZ 75 derivatives stuck with that system in having no de-cocker switch at all and could only do so by pulling the trigger while regulating the hammer (not recommended on a loaded chamber). Between CZ 75s having such a questionable safety option and having been invented behind the Iron Curtain for 9x19mm Parabellum (a cartridge that was not Warsaw Pact standard) is made sensible by the fact that the Koucky brothers were granted a clean slate to produce whatever they wanted and the result was an export-geared competition piece that in the 21st century happened to make for a great service pistol in an age that process usually occurs the other way around.
Of all systems covered so far this has the highest versatility, able to be carried 1) Browning-style used in single-action only, 2) SIG-style with a double-action first shot, or 3) both combined for inspection which, like all systems involving multiple manual safeties, is complex and unnecessary for defensive carry. The CZ 75 itself, having finally made it West after the fall of the Iron Curtain, carries a big reputation among those who have it because of the accuracy and reliability it offers at a price point such strong positives can be tricky to find. One plus of this more complex manual of arms is its adaptability: anyone already accustomed to any of the other three systems already mentioned can operate a CZ 75 or derivative the same way and call it good; for the more specific or discerning there are single-action only and de-cocker only CZ 75s made too.
Law Enforcement Standard (Double-Action Only)
Before wrapping up with the final two systems there is one other pertinent matter to them and in part to those already covered. Going back to the start of the autoloading age police firearms were just like the military (how little changes!) in being "service grade" but otherwise boasting no substantive difference from those available on the market. Revolvers continued as police standard through the 1980s, and in earlier days the double-action models from Colt and Smith & Wesson were received well.
Even though the job of police is to run towards trouble rather than away from it, officers are like anyone else in that their training has its limits and their best hope is never having to draw their weapons. After action reviews found a trend in which police were cocking their wheel guns into single-action when the tension ran high, the issue being the lighter trigger pull weight coupled with adrenaline raising odds of negligent discharge with tragic results. A mechanical solution was found in defaulting to double-action only, and soon enough pistols were made specifically for police work that excised single-action mode.
Most of us are not law enforcement and have no reason to think or train like police, however the added safety of double-action only is undeniable and for better or worse pistol models and designs successful in law enforcement accordingly earn great general market appeal. As police transitioned to semi-autos the trend followed three major categories: 1) some departments used single-action only models like the 1911 so no double-action option, but the manual safety still worked just fine (particularly for officers who previously served in the military and already knew the manual of arms); 2) standard models were issued with strict rules keeping to the double-action first shot, or else a double-action only variant; 3) in recent years strikers have become favored which are double-action only by default, sometimes with variants for certain agencies that have a specific trigger weight adjustment for their needs. Though Hi-Powers, SIGs and Berettas (among many others) were designed for military service they also offer double-action only variants for police and a lot of civilians have their reasons for acquiring them.
Glock (Striker-Fired without Manual Safety)
It was actually the Heckler & Koch VP70 which pioneered mating polymer frame to striker, but when Gaston Glock (pictured) decided to go for Austria's pistol contract a decade later he only wanted to keep things simple because this was his first dabble with firearms. He was, however, very adept with polymers and it shows. Austria has a history of unusual arms design that is also quite innovative even when not successful, but as interesting as Steyr Arms has been for over 150 years it is relative newcomer Glock that can claim to have single-handedly redefined what a pistol is to most people who think peripherally about the topic. The line's solid reliability and cost-effectiveness have made it a 21st century standard among military and law enforcement.
But that does not automatically translate to usefulness for everyday defense-minded citizens who do not have to subject themselves to the stipulations of mass logistics that government agencies do. Not just Glock but any modern Walther, the current Smith & Wesson M&P line, the SIG P300 family, and a host of other manufacturers produce options for civilians and governments following the same philosophy of a striker mechanism operating on top of a polymer frame. Of course these two categories just happen to work well together but are technically independent, what with metal-framed strikers and hammer-fired plastics out there too.
While technically double-action only strikers can have trigger tuning closer to single-action pull. In any case the consistency of that pull is an undeniable asset, but what weight may work better (since there is no hammer to cock) for the individual means if one is considering this type there ought to be more "try before you buy" in that determination. For all it has going for it Glock is known to be a relative loser in the comfort/ergonomics category, so for the civilian who will fire only a fraction of the rounds of a public serviceman in his/her lifetime reports concur there are better choices (unless going for multiple-caliber conversions which Glock is better for than most anyone else, just have to stick with the same frame size).
HK/Hybrid (Any or All of the Above)
Granted the best-known HK system is their CETME-type for longarms introduced with the G3 rifle then popularized via the MP5 submachine gun, however they have a strong handgun history of its own. The HK4 had the unique feature of being convertible to any of the 4 subcompact calibers, and the VP70 was mentioned earlier. The P9 and P7 are perhaps most famous in the Western Hemisphere for their screen appearances, but it was the succeeding P8 (as designated by the Germans) that kicked off their modern era.
Its project and general market name translates to "Universal Self-Loading Pistol" abbreviated USP. Its starting point was the MK23, USSOCOM's early 1990s stipulation for a handgun useful offensively as well as for defense (succeeded by the HK45 Compact, designation MK24). But what started with the USP line was the staggering variety of operating choices.
A number system is followed (necessitating prudent research), odd for regular and even for left-handed, and this carries into the rest of the family including the P2000, HK45, P30 and the new Volkspistoles. You can choose what controls you want (or lack thereof) and how they function: 1) a "complete" hybrid like a Walther with Browning capacity via a single control that functions as a manual locked safety, unlocked to accommodate a double-action first shot, AND a SIG-like de-cocking lever that functions strictly as such; 2) SIG-style in which the control lever is a de-cocker but not a safety; 3) law enforcement double-action only with no external controls (HK also offers a lighter double-action trigger module compatible with this and any other variant); 4) CZ-style in which the control is just a manual safety. The capability to transition to this platform from any other is a tremendous asset, and HK has earned a reputation for reliability that rivals Glock.
Conclusion
These are all the major operating systems available today: whatever does not directly use one of these uses something closely related. Their primary producers and inventors are noted but no one is exclusive over any domain so it is good to know that in sorting options for subcompact carry, compact versatility and full-size power & accuracy use of common systems is possible as well as a good training idea. Still the bottom line is to go with what works for you and safety system is one consideration among several.