Firearms safety was a concern as early as 1860. Among the first safety features nearly universally adopted was the trigger guard. But several more kinds of gun safeties exist today. There are active safeties, such as safety levers, to passive safeties like the firing pin block.
After the trigger guard came a half-cock notch in the gun lock. Most revolvers were single-action, and the half cock notch caught the hammer if you slipped during the cocking process. That prevented the hammer firing. A special safety cylinder was designed for the Colt 1860 that allowed the hammer to rest between cylinders — one of the first of its kind. And the Starr revolver was factory equipped with such a device.
Early Revolver Safety
For the most part, six shooters were carried with an empty cylinder under the hammer. By the 1880s, a rebound-type hammer was developed. The hammer spring ran the hammer forward to fire the revolver then the rebound spring moved the hammer away from the cartridge and kept it there. Hammer blocks were universal in quality double-action revolvers by 1900 but lagged behind for many years in single-actions.
Though not altogether nonexistent, manual trigger and hammer locking safeties were rare on revolvers. A huge advancement in revolver safety was the passive safety transfer bar. A passive safety requires no active manipulation. The transfer bar, in this case, is between the hammer and the firing pin, preventing the hammer from touching the firing pin. As the trigger is fully pressed, the trigger bar rises. The hammer falls and transfers energy to the transfer bar, and the transfer bar strikes the firing pin. That releases the trigger, and the hammer springs back. These are the safest revolvers ever manufactured.
Revolver design is also responsible for a common feature on single-action self-loading pistols: the grip safety. The grip safety would lock the action until the revolver was firmly grasped and the lever depressed. These were called hammerless revolvers, as the hammer was concealed and could not be cocked for single-action fire.
Safety Devices for Self-Loading Firearms
With the introduction of self-loading pistols came a dizzying number of safety devices invented. Practically all that are in use today were invented before 1920. The most important early development was the inertia firing pin. Firing pins were once full length and rested on the primer of a chambered cartridge. Inertia firing pins are shorter than the firing pin channel and do not rest on the primer when the hammer is down. The hammer smacks the firing pin on firing and drives it forward, firing the pistol. The firing pin is then retracted to its original position by the firing pin spring. This isn’t perfect, however. If the gun is dropped on the muzzle, the firing pin may take a run forward and fire the pistol.
There are two means of making the pistol drop-safe. One — widely used in single-action automatic pistols — uses an extra power firing pin spring and lightweight firing pin to reduce firing pin inertia. The other type is the firing pin block or drop safety. The firing pin or striker is held in place until the trigger is fully pressed, firing the pistol and moving the firing pin block out of the way. Firing pin blocks are now basically universal.
Other Types of Safeties
The Colt 1911 handgun had a unique combination of safety features. A grip safety prevented a cavalryman from shooting his own horse if the pistol were dropped. And the slide-lock safety allowed carrying the pistol hammer to the rear with safety on, making for a very rapid first shot with increased accuracy.
The slide-lock safety and grip safety were eventually complemented by firing pin blocks or extra power firing pin springs, while other handguns used safety levers that were ill-suited for personal defense. The Astra 600 features a safety in front of the trigger. And the original SIG P210 also used this type of trigger blocking safety. While effective, they are difficult to use quickly.
One safety feature designed to catch the hammer from falling is the half-cock notch. However, this is not a safe carry position. The half cock notch is not strong enough and would drop the hammer if bumped hard enough. Never carry a single-action pistol on half cock!
Later single-action safety levers sometimes lock the hammer but not the slide and allow the pistol to be loaded while on safe. An uncommon safety feature today is the magazine disconnect. The Browning High Power and Smith & Wesson 39/59/5906 pistols among others use this “magazine safety.” The pistol cannot be fired with the magazine removed.
Safety Features Moving Forward
The most influential handgun of the 1930s was the Walther P38. This pistol led to the Beretta 92 combat pistol. The Walther double-action first-shot design is seen as a safety feature. That safety lever set the pace for other handguns. When applied, the safety safely dropped the hammer from full cock. The hammer fell but was blocked from striking the firing pin by the safety itself. Double-action pistols sometimes use two-piece firing pins as well. With the safety applied, the trigger is inoperable, and the hammer cannot rest on the firing pin. This is a very solid system widely adopted.
The SIG decocker is an ergonomic design located in front of the trigger guard. Originally developed in 1938 for the JP Sauer, this lever was necessary as the pistol had a concealed hammer that could not be lowered manually. In the original design, a hard press on the decocker would cock the hammer for single-action fire. This pistol also featured a manual safety on the slide. Slide-mounted safety levers are not as ergonomic as those mounted on the frame but are positive in function. The SIG decocker was adopted for the highly successful SIG P220 and later P series pistols. Though it has safety features, there is no manual safety.
The CZ 75 in its original design is a selective double-action pistol. The safety cannot be applied when the hammer is down. The pistol’s first shot is fired double-action. After the first shot, the hammer is cocked by the slide and the safety may be applied. This pistol was not expressly designed to be carried cocked and safety on but to allow the pistol to be carried safely during tactical movement without decocking the hammer.
Many of these types are much less popular today. A popular defensive pistol is the striker-fired polymer-framed handgun. The majority are double-action-only like the Glock. Some, like the Canik TP9 and Springfield XD, are single action. Glock has a firing pin block and a trigger lever set in the trigger face. This lever blocks trigger motion unless the lever if fully pressed. This prevents lateral discharge if the trigger is snagged. Some pistols feature a manual safety. A mechanical safety is good to have, as are safety features. But true safety lies with the shooter.