Handguns and how they work are a product of their time, as a solution to a perceived problem. But the designs that come forth outlast their designers, even when the problem ceases to be.
Take striker-fired handguns as an example. Chances are, if you are carrying a handgun on duty or for concealed carry, it is likely some variety of striker action handgun. Striker guns are nothing new, but they arose in response to the perceived problems of hammer-fired designs over a century ago.
Both striker and hammer-fired guns have evolved since then and users of both are adamant that striker actions or hammer-fired actions are better or worse than one another. But even in these broad categories, there are differences, disadvantages, and advantages.
Among hammer-fired handguns, there are models with internal and external hammers. Here is a rundown of why they exist and why you might pick one.
External Hammer Fired Handguns: The First and Best?
The first handguns were little more than shorter versions of long guns with similar actions. Early guns were muzzleloaders powered by easy-to-make leaf springs and hammers that provided an impact to set the gun off.
After the American Civil War, more compact coil springs were pioneered. These springs were less brittle and took up less space, which could make for a more compact design and perhaps even do away with an exposed hammer entirely.
Coil springs wrapped around firing pins gave us the first striker actions, which manifested in the first bolt action rifles like the French Gras and the German Mauser. Eventually, that concept would be coopted into the first striker-fired handguns at the turn of the 20th century. As it happens, coil spring technology did not completely do away with the tradition of hammer-fired actions, but it did evolve them.
Typical revolvers of that time had a leaf spring housed in the grip. New autoloading pistols like the Colt 1911 used a small coil spring to power the hammer with more than enough room to use the grip to house the ammunition in a magazine.
Although the first internal hammer handguns were already on the market by the time the 1911 was adopted by the US Army, hammer-fired guns were the rule. Revolvers continued to use hammers and in the new world of autoloading pistols, the exposed hammer remained a viable option as it was familiar to all shooters. Also, the condition of the firearm and whether or not it was ready to fire was immediately apparent. But having an exposed hammer on a handgun posed issues, both old and new, where internal hammer handguns and striker-action handguns took up the slack.
Internal Hammers and the Nuances of Hammer-Fired Carry
Most hammer-fired handguns have an exposed hammer that you can see and manipulate. Internal hammer-fired guns still have a hammer but it is sealed within the frame or slide.
The greatest case for an internal hammer pistol is because it is a naturally snag-free design. On drawing a pistol from concealment, the hammer spur could catch on a pocket or garments and prevent the user from deploying the handgun quickly.
The trend toward removing the hammer spur began with the first double-action revolvers that began to find favor in the 1880s. The hammer spur would simply be ground off and the revolver could only be fired by simply pulling the trigger, making it a double action only gun, as the single action capability of cocking the hammer for a lighter trigger is now taken away.
In the 1890s, gun makers took the concept a step further by entirely enclosing the hammer in the frame of their new generation of break-top revolvers like the Smith & Wesson Centennial and the Iver Johnson Safety Hammerless.
Revolvers like these were double action only as a factory option and were the first in a long line of “hammerless” revolvers that continue today, but the first internal hammer semi-automatics were only a few years away.
The Colt Model 1903 and Model 1908 Pocket models, chambered in .32 ACP and .380 ACP respectively, were two early examples of internal hammer pistols. The slide cocks the hammer, and the pistol is carried with a manual safety, but on the draw there are no snag points.
In addition to being snag-free, these early revolvers and semi-automatic pistols enjoyed the benefit of being more drop safe than their exposed hammer counterparts. In an era before hammer blocks and firing pin safeties, having the hammer sealed into the action prevented it from taking a blow that would break the sear notch with the trigger and discharge the pistol.
A tertiary benefit of an internal hammer pistol is that it is sealed within the action and more immune to dirt, sand, lint, and other ingress. Such debris could impede an exposed hammer from firing the handgun when needed, as it could pack into the hammer channel. But despite the benefits, internal hammer handguns underperformed in the marketplace compared to their exposed hammer counterparts.
Both configurations also have to compete with striker-fired handguns that are mechanically simpler but afford the same snag free profile of internal hammer options.
Internal Hammer vs. External Hammer Pistols: The Here and Now
External hammer pistols are intimately familiar and approachable, as you know the condition of carry and we infer from history that older designs tend to work. It also helps that hammer-fired handguns tend to have smoother, more consistent triggers than striker-action options.
Interestingly, double action only hammerless revolvers tend to have lighter triggers compared to their exposed hammer counterparts. By picking an internal hammer model, we give up being able to see the hammer and having it enclosed from the elements like a striker pistol, but with a potentially better shooting experience overall.
The most popular internal hammer design is, by far, the Smith & Wesson Centennial Airweight. Built on the J-frame, the Centennial has an enclosed hammer and comes in a number of calibers and finishes.
Since its introduction in 1957, it has also been widely copied with the Ruger LCR, Taurus 850, and Charter Arms Off Duty being only a few of the better known facsimiles. It is more surprising just how many internal hammer semi-auto pistols remain and are put into production every year.
Most FN 5.7 pistols ranging from the FN Five-seveN to the Ruger 57, are hammer fired single-action designs. The Ruger Security Nine and Ruger LCP are also internal hammer designs. Smith & Wesson’s M&P 22 and EZ line of .380 ACP and 9mm handguns are also internal hammer fired.
Although the popularity of exposed hammer and striker-fired guns continues, it is clear that a growing number of manufacturers understand the benefits of internal hammer platforms and are making good use of them.
