A bolt-action firearm is a type that is manually operated (i.e. by hand), specifically the opening and closing of the breech is controlled manually. The term "action" references the means by which a firearm operates.

Typically, the bolt consists of a tube of metal inside of which the firing mechanism is housed, and which has at the front or rear of the tube several metal knobs, or "lugs", which serve to lock the bolt in place. The operation can be done via a rotating bolt, a lever, or a number of systems. For example, one setup is a straight-pull design that use a rotating bolt, such as the German Blaser R93 rifle. Straight pull designs designs have seen a great deal of use, though manual turn-bolt designs are what most commonly thought of in refernce to a bolt-action design do to the type ubiquity. As a result the bolt-action term is often reserved for more modern types of rotating bolt-designs when talking about a specific weapon's type of action, however both straight pull and rotating bolt rifles are types of bolt-action rifles. Lever action and Pump action weapon's must still operate the bolt, but they are usually grouped seperately from bolt-actions that are operated by a handle directly attached to a rotating bolt.

Most bolt-action firearms are fed by internal magazines loaded by hand, by en bloc, or stripper clips, though a number of designs have had a detachable magazine or independent magazine, or even no magazine at all require each round to be independently loaded. Typically, the capacity has been limited to several rounds, as it can permit the magazine to be flush with the bottom of the rifle, reduce the weight, or prevent mud and dirt from entering. A number of older bolt actions had a tube magazine, such as along the length of the barrel.

In weapons other than large rifles, such as pistols and cannons, there were some manually operated breech loading weapons. However, the Dreyse Needle fire rifle was the first breech-loader to use a rotating bolt design. Johann Nicholas von Dreyse's rifle of 1838 was accepted into service by Prussia in 1841, which was in turn developed into the Prussian Model 1849. The design was a single-shot breach loader, and had the now familiar arm sticking out the bolt to turn and open the chamber. The entire reloading sequence was a more complex procedure then later designs however, as the firing pin had to be independently primed and activated, and the lever was only used to move the bolt.

Throughout the 1800s breech-loading bolt-actions contintued to develop following a steady progression, seeing widespread adoption and continual improvemets in design. WWI marked the height of the type's use though automatic loading designs were starting to be used.

During and after World War II, the military bolt-action rifle was superseded with the semi-automatic rifle and later assault rifles. However, the bolt-action is still common among sniper rifles, as snipers value the design's potential for superior accuracy, reliability, and the ability to control loading over the faster rate of fire that alternatives allow. There are however, many semi-automatic sniper rifle designs in existence, especially in the designated marksmen role.

See also

• Krag-Jørgensen
• Lee-Enfield
• Mannlicher-Carcano
• Mauser
• Mosin-Nagant
• Springfield 1903 rifle
• Spencer repeating rifle