Firearm actions play a central role in how guns load, fire, and eject spent cartridges. Over centuries, designers have developed a wide variety of firearm action types, from simple hinged blocks to complex gas-operated systems.
Below, we’ll explore types of gun actions explained in detail—highlighting each major category along the way. Whether you’re comparing bolt action vs semi-auto, searching for the best single-shot design, or simply curious about the rifles and shotguns of old, this guide will help you understand the engineering behind every trigger pull.
Table of Contents
What is an “Action”?
In a firearm, the “action” refers to the mechanism that handles loading, firing, and ejecting. For muzzleloaders, which are loaded at the front of the barrel, the notion of a breech-based mechanism doesn’t apply—they lacked anything we’d call a “modern action.” But once designers began crafting breech-loading firearms, inventors introduced a vast range of firearm action types to make guns more convenient, reliable, and quick to operate.
While there are many ways that we could conceivably classify firearm actions, the simplest way is to break them into two major groups. Either a single-shot action or a repeating action.
Single-Shot Actions: Classic Simplicity
Single-shot firearms contain only a single round at any one time. You must manually load a fresh cartridge after each shot. They lack magazines for additional ammunition, though there are some exceptions. Despite their lower rate of fire, these actions often exhibit mechanical elegance and remarkable accuracy—making them popular among target shooters, hunters, and enthusiasts of historical weapons.
Early attempts to improve the design of firearms with breech loading mechanisms fell into the following groups.
Dropping Block
Dropping block actions incorporate a breechblock that literally “drops” vertically into the receiver to open the chamber. Often connected to an underlever, operating that lever lowers the block, allowing you to insert a round.
Tilting Block (Pivoting Block)
Some dropping blocks hinge on a pin at the rear of the breechblock. The block tilts downward and forward when the lever moves. Famous pivoting-block rifles include the Peabody and Peabody–Martini designs.
The Ballard action, manufactured by Marlin in the late 19th century, also used a self-cocking tilting block—highly revered in “Creedmoor” long-range shooting competitions.Falling Block
Instead of hinging, a falling block slides straight down. The Sharps rifle and the more modern Ruger No. 1 exemplify this design, known for robust strength and accuracy.
Rolling Block
In a rolling block design, the breechblock is half-cylinder in shape, pivoting on a pin so it “rolls” into position. The hammer itself locks the breech closed. Remington rolling block rifles dominated in the late 1800s, admired for reliability and simplicity.
Trapdoor or Hinged Block
Early metallic cartridge conversions for muzzleloaders—like the Allin “trapdoor” system at the U.S. Springfield Armory—featured a hinged breechblock that flips forward or to the side. The British had the Snider–Enfield, which swung sideways, but quickly moved on to the Martini action. Meanwhile, Americans produced the Springfield Model 1873 “Trapdoor” for decades, notably fielded during the Indian Wars and into the Spanish–American War.
Break Action
Most commonly seen on shotguns, break action guns physically “break open” at the rear of the barrel to load and unload shells. Side-by-side and over-under shotguns often use this design, as do many combination guns with both rifle and shotgun barrels.
Eccentric Screw Action (“Cannon Breech”)
First seen on the M1867 Werndl–Holub rifle, then on the 1897 French 75 mm field gun, and even the Magnum Research Lone Eagle pistol. A rotating drum acts as the breech closure, offset from the bore’s axis. When aligned, the firing pin is free to strike the primer; when rotated, the breech opens so you can load a new round.
Other Unique Single-Shot Designs
- Bolt Actions: Though we often think of bolt rifles as repeating arms, the earliest bolt-action military breechloaders—like the Prussian needle gun (1841), Chassepot (1866), and the first Russian Berdan—were single-shot.
- Ferguson Rifle (1770s): Major Patrick Ferguson’s screw-threaded breechblock rifle, requiring ball and loose powder, but still breech-loaded.
- Hall Rifle (1830s–1840s): U.S. cavalry breechloader that pivoted up to load a paper cartridge, infamous for gas leakage at the breech.
- Kammerlader (Norway): Featured a crank-based breech for paper cartridges, eventually converted to rimfire.
- Tarpley Carbine: A hinged falling block from the Confederate era.
- Morse Carbine: Experimental centerfire carbine from the 1850s—few produced.
- Joslyn Rifle: Early rimfire breechloader used by both U.S. Army and Navy. Later refined with a pivoting breech “cap.”
- Rising Breech Carbine: A Confederate design used in the American Civil War.
Repeating Actions: Multi-Shot Innovations
As technologies evolved and more rapid fire was needed for armies and civilians alike, designers responded with repeating designs. While have been attempts to increase rate of fire though retrofitting previous designs in some instances, the following action types are much more what we would consider to be “modern” actions.
Revolver
Most revolve-based firearms are handguns, though revolving rifles and shotguns have existed. A cylinder holds multiple rounds, rotating to align each cartridge with the barrel before firing. Classic examples include the Smith & Wesson Model 3 and Colt Model 1889. Some revolve-based actions can be single-action (hammer cocked manually) or double-action (trigger pull both cocks and fires).
While most think of pistols when they hear the word revolver
Rotating Bolt Action
Bolt action vs semi-auto is a common question among shooters, and the rotating bolt has shaped that conversation significantly. Most turn-bolt rifles demand the shooter lift the bolt handle, pull it back, then push it forward and rotate it back down. The Mauser system is legendary, but the Lee–Enfield and Mosin–Nagant also made their mark on military history.
Straight-Pull Action
Instead of rotating the bolt handle, a straight-pull action uses cams and ball-bearing locks. It shortens the motion needed to cycle the bolt. Examples include the Swiss K31 rifle and the modern Blaser R8. In biathlon, straight-pull .22 rifles from Anschütz dominate, maximizing speed while staying within race rules. While not nearly as common today as a standard bolt action they do have a strong following and the action type continues to be used today.
Pump Action
Common to shotguns (like the Remington 870, Mossberg 500, and Winchester Model 1912), the shooter slides a fore-end grip to eject the spent shell and chamber a new one. Pump-action rifles exist as well, but shotguns remain the icon of this mechanism. Early designs were “clunky”, yet not too dissimilar to modern pump actions.
Lever Action
Iconically “Old West,” lever actions use a loop under the trigger guard to cycle cartridges. Examples include the Henry Model 1860 and Winchester Model 1894. Hunters admire them for speed and style, while collectors prize them for their American frontier history. Today the lever action continues to be iterated upon by companies like Henry Repeating Arms
Bolt Release / Lever Release (Hybrid)
A relatively rare concept that partially self-ejects spent cases (often via blowback or gas) but requires manually releasing the bolt catch to load the next round. In places with restrictive gun laws, these “semi-semi-auto” rifles attempt to comply by removing fully automatic cycling from the design. Examples include certain MARS action rifles in the UK or specialized European hunting shotguns. The action design only really continues to see use due draconian to firearms laws outside of the US.
Self-Loading Firearms
Semi-automatic firearms harness energy from the fired round to eject spent cases and load fresh ones—no manual action required between shots (unlike bolt action vs semi-auto, where the shooter must manipulate the bolt for each shot in a bolt gun). Early attempts used muzzle devices to capture energy from the gasses released, others simply used weight and springs to keep the action closed until the right time. Today self-loading firearms are far more complex and innovative.
Blowback Operation
A simple system using spring tension and bolt mass to keep the breech closed. When the round fires, the bolt moves rearward under pressure, ejecting the spent case. Uzi submachine guns and many .22 rimfire pistols use simple blowback. Delayed blowback methods (like roller-delayed or lever-delayed) manage higher calibers.
Blow-Forward Operation
An unconventional approach where the breech stays static, and the barrel itself moves forward from the pressure. Rare examples include the Steyr Mannlicher M1894. The design never reached mainstream success, but remains an intriguing footnote.
Recoil Operation
Used in many popular handguns and machine guns, recoil systems keep the breech locked until pressure drops. Then the barrel and bolt separate. Sub-types include short-recoil (the most common of them all due to guns like the M1911, Glock series) and long-recoil (e.g., Browning Auto-5 shotgun), plus inertia-driven systems (e.g., Benelli shotguns).
Gas Operation
Tapping high-pressure gas from the barrel to drive pistons or directly push the bolt. Gas systems dominate modern military rifles (like the AR-15/M16 and AK-47). They come in three broad forms: long-stroke piston (AK-47), short-stroke piston (SKS), and direct impingement (AR-15).
Long-stroke systems use a gas piston that travels the same length as the bolt. The bolt and gas piston often all move as one unit.
Short Stoke gas piston systems still have a piston but it is detached from the bolt that it is operating and travels a shorter distance than the bolt of the rifle.
Direct impingement, common on most AR’s today, tap gas from the barrel and use it without a piston to unlock the bolt and cycle the action.
One final system that I hinted at earlier was the “Bang” system. In modern gas operated systems, gas is bled from the barrel, usually about 2/3rds of the way down the barrel. The system was complicated, and never really went anywhere, but the idea would get others thinking about more practical solutions.
Final Thoughts - Policing the Brass
From the earliest hinged breech blocks to intricate gas-powered autoloaders, these firearm action types show the creativity and craftsmanship at the heart of gun design. Generations of innovators have tried to blend speed, power, and reliability in new ways. Whether it’s bolt action vs semi-auto, or one of the many types of gun actions explained, there’s a deep well of history behind each system we handle today.
Embrace the Story:
Every time you chamber a round—no matter the action—you’re part of centuries of evolution in firearms. Understanding these different mechanisms not only helps you choose the right gun but also brings deeper appreciation for the remarkable engineering that underpins every shot.
