Cylinder (firearms)
Rotating multi-chamber component that sequentially feeds cartridges into a revolver's barrel.
In a revolver, the cylinder is the rotating, cylindrical component that holds multiple chambers, each designed to accept one cartridge. This part spins around a central axis within the revolver's mechanism, bringing each chamber into line with the barrel bore one after another for successive shots. When the gun is cocked, the cylinder advances by one chamber—rotating by 72 degrees for a five-chamber cylinder, 60 degrees for six chambers, 51.43 degrees for seven, 45 degrees for eight, 40 degrees for nine, and 36 degrees for ten chambers. Acting like a rotary magazine, the cylinder stores ammunition inside the revolver, enabling multiple firings before reloading is necessary.
Most revolver cylinders are built to hold six cartridges, which is why revolvers are often called six-guns or six-shooters. However, some small-frame concealable models, like the Smith & Wesson Model 638, use a five-shot cylinder due to their compact size and limited space. Other examples include the Nagant M1895 with a seven-shot cylinder, the Webley-Fosbery Automatic Revolver in .38 ACP with eight shots, the LeMat Revolver with nine shots, and the Smith & Wesson Model 617 in .22 Long Rifle with ten shots.
Cylinders are generally not meant to be removed from the firearm except for cleaning or maintenance. For faster reloading, speedloaders or moon clips are used, but these only work with top-break and swing-out cylinder revolvers. Revolvers with fixed cylinders must be loaded and unloaded one chamber at a time.
**Fluted Cylinder Designs** Fluted cylinders are common on revolvers and date back to early revolving firearms, such as the Elisha Collier flintlock revolvers. By cutting flutes into the cylinder, manufacturers reduce the firearm's weight without sacrificing strength. Fluting also makes it easier to rotate the cylinder by hand, which was helpful for loading and unloading early manually rotated firearms. While pepperbox revolvers often had ribbed or fluted cylinders, most traditional percussion cap and ball revolvers had non-fluted cylinders. Samuel Colt and his company experimented with fluted cylinders on several models in the 1850s and 1860s, including the Colt Model 1862 Pocket Police, which came standard with a fluted cylinder during the American Civil War. Smith & Wesson followed with fluted cylinders on their Model No. 1 Third Issue and Model No.
- Common capacity
- 6 cartridges
- Five shot example
- Smith & Wesson Model 638
- Seven shot example
- Nagant M1895
- Eight shot example
- Webley-Fosbery Automatic Revolver in .38 ACP
- Nine shot example
- LeMat Revolver
- Ten shot example
- Smith & Wesson Model 617 in .22 Long Rifle
- Indexing angles
- 72° for 5 chambers, 60° for 6, 51.43° for 7, 45° for 8, 40° for 9, 36° for 10
Lore & Background
Fluted cylinders are commonly found on revolvers and go back to early revolving firearms, including the Elisha Collier flintlock revolvers. By fluting the cylinder, manufacturers can reduce weight without compromising adequate strength. During the percussion cap and ball era, most traditional revolvers had non-fluted cylinders. Samuel Colt and Colt's Patent Fire Arms Manufacturing Company experimented with fluted cylinders on several models in the 1850s and 1860s, including the Colt Model 1862 Pocket Police with a fluted cylinder as standard during the American Civil War. Smith & Wesson released their Model No. 1 Third Issue and Model No. 1-1/2 Second Issue revolvers in 1868 with fluted cylinders, followed by the Smith & Wesson Model 3 in 1870; thereafter, fluted cylinders were essentially standard on revolvers, including the Colt Single Action Army released in 1873.
Fixed-cylinder designs were the first generation of cartridge revolvers, converted from caplock designs. In many of these, the pin on which the cylinder revolved was removed and the cylinder was taken from the gun for loading. Later models used a loading gate at the rear that allowed one cartridge at a time to be inserted, while a rod under the barrel could eject the fired case. The loading gate on original Colt designs is on the right side, which may favor left-handed users; this was done because these pistols were intended for use with cavalry, with the revolver and reins held in the left hand while the right hand was free to eject and load cartridges. Fixed-cylinder revolvers are inherently strong designs because the cylinder is firmly attached at the front and rear of the frame, and the frame is typically full thickness all the way around.
Top-break revolvers feature a frame hinged at the bottom front of the cylinder; releasing the lock and pushing the barrel down brings the cylinder up, exposing the rear for reloading. In most top-break revolvers, the act of pivoting the barrel and cylinder operates an extractor that pushes cartridges back far enough to fall free. Since the frame is in two parts held together by a latch, top-break revolvers cannot handle high pressure or magnum-type rounds. Swing-out cylinders, invented by several people in the 1850s and 1860s, mount the cylinder on a pivot coaxial with the chambers, swinging out and down (to the left in most cases). An extractor operated by a rod projecting from the front of the cylinder assembly pushes all fired rounds free simultaneously.
Reader's Guide
The cylinder is the defining component of the revolver, enabling multiple shots without reloading by rotating to align each chamber with the barrel. Its design has evolved through several loading mechanisms: fixed cylinders with loading gates, top-break designs with automatic extraction, and swing-out cylinders that allow simultaneous ejection and reloading. The cylinder's capacity varies widely, from five-shot small-frame concealable revolvers to ten-shot models in .22 Long Rifle. Fluting reduces weight and aids manual rotation, while non-fluted cylinders are sometimes used for engraving or with powerful cartridges. Fixed-cylinder revolvers remain the strongest design, capable of handling the most powerful cartridges, but are the slowest to load. Top-break revolvers, though largely extinct in firearms, are still common in airguns. Swing-out cylinders became the most widely adopted method by the end of the 20th century, though the crane that supports the cylinder is a weak point; flicking the cylinder open with a wrist motion can bend the crane over time, causing dangerous misalignment. The cylinder's legacy is central to the revolver's identity as a reliable, multi-shot firearm.
Did You Know?
- The cylinder indexes by 72° for a five-chamber revolver, 60° for six chambers, 51.43° for seven, 45° for eight, 40° for nine, and 36° for ten chambers.
- The Nagant M1895 revolver has a 7-shot cylinder, while the LeMat Revolver has a 9-shot cylinder.
- The loading gate on original Colt single-action revolvers is on the right side, intended for cavalry use with the left hand holding the reins.
- Flicking a swing-out cylinder open with a wrist motion can bend the crane, throwing the cylinder out of alignment with the barrel.
Frequently Asked Questions
What is the cylinder in a revolver?
The cylinder is the spinning, barrel-shaped core of a revolver that stores loaded cartridges in individual chambers arranged around a central axis. It functions as the gun's rotary magazine, rotating to bring each chamber into alignment with the barrel bore for the next shot.
How many rounds does a standard revolver cylinder hold?
Six cartridges is the most common capacity, found in the vast majority of production revolvers. That said, manufacturers have produced cylinders with anywhere from five chambers (e.g., Smith & Wesson Model 638) up to ten (e.g., Smith & Wesson Model 617 in .22 Long Rifle).
How does the cylinder advance to the next chamber?
Each time the hammer is cocked, a fluted notch on the cylinder's face engages the cylinder stop, rotating the part by a fixed angular increment. A six-chamber cylinder turns 60 degrees per cycle, while a five-chamber design like the S&W Model 638 rotates 72 degrees.
What are some examples of revolvers with unusual cylinder capacities?
The Nagant M1895 uses a seven-chamber cylinder (51.43° per step), the Webley-Fosbery Automatic Revolver in .38 ACP has eight chambers, and the LeMat Revolver features nine. The ten-chamber Smith & Wesson Model 617 in .22 LR represents the upper end of production revolver capacity.
Why is the cylinder considered the defining feature of a revolver?
Unlike semi-automatic pistols that feed from a linear magazine, the revolver's cylinder stores ammunition radially around a central axis, allowing the next round to be indexed with a single cocking motion. This rotary, multi-chamber design is what fundamentally distinguishes a revolver from every other handgun type.
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