Cooper Underhammer Pepperbox
J.R. Cooper · Revolver · Discontinued · 1843
Also known as: J.R. Cooper Patent Pepperbox, Cooper Patent Under-Hammer Pepperbox Revolver, Cooper Ring-Trigger Pepperbox
Overview
The Cooper Underhammer Pepperbox is a mid-19th-century British percussion cap-and-ball revolver patented by John Rock Cooper of Birmingham in 1843. Its six barrels are bored from a single solid steel cylinder that revolves as a unit, and it is fired by an unusual underhammer mechanism whose percussion nipples sit beneath the barrel cluster and are struck from below. A ring trigger operating the self-cocking double-action lock advances the barrels and releases the hammer in a single pull. Typically chambered around .36 caliber, it was a popular personal-defense sidearm sold on the British civilian market until roughly the mid-1850s.
Specifications
| Weight (empty) | 620 g (21.9 oz) |
| Overall Length | 197 mm (7.76") |
| Barrel Length | 89 mm (3.50") |
| Action Type | Double Action |
| Firing Mechanism | Percussion |
| Trigger Type | Double Action |
| Magazine Capacity | 6 rounds |
| Magazine Type | Internal |
| Muzzle Velocity | 229 m/s (751 fps) |
| Effective Range | 10 m (11 yd) |
| Maximum Range | 45 m (49 yd) |
| Barrel Rifling | None |
| Frame Material | German Silver |
| Barrel Material | Steel |
| Stock Material | Walnut |
| Finish | Blued |
Calibers
- .36 Caliber Percussion (Cap and Ball) · primary — also known as .36 cal, .36 percussion, 9.1mm, 80-bore, 60-bore
Features
- Firing modes: Repeating
- Feed systems: Muzzle Loaded Percussion
- Features: Underhammer Mechanism, Ring Trigger, Self Cocking Double Action, Six Barrel Revolving Cluster, Nickel Silver Frame
Service history
Operators
- British civilian market · adopted 1843
Production
Production years: 1843-1853
Produced in Birmingham, England; exact production totals unrecorded
Origin
Country of origin: United Kingdom
Designer: John Rock Cooper
Discontinued: 1853
Notes
Bore diameters vary between surviving examples, quoted in the period British system as roughly 80-bore to 60-bore (about .36 to .40 caliber). Higher-grade examples used a solid nickel-silver (German silver) frame rather than plated brass, with walnut grip scales.
Background
John Rock Cooper's 1843 patent placed the hammer beneath the barrel cluster, a layout that kept the lock out of the shooter's line of sight and gave the compact pepperbox an unusually clean, hammerless profile for a percussion revolver of its day.