Rifleman Q&A: Shotgun Proofmarks?

posted on October 24, 2021

Q. How do I tell if an old or new shotgun has been “proofed”? My Italian guns seem to be covered with proofmarks—as do a couple old Belgian guns I have—but my American guns don’t seem to have any. How are guns proofed and how do you tell?

A. Proofmarks could be a story or a book themselves. In a nutshell, much can be determined about the origins and to a wide extent the date of manufacture of some shotguns just by examining the proofmarks. A good sampling of proofmarks can be found in the NRA Firearms Fact Book and elsewhere.

Older double guns will primarily carry Belgian or British proofmarks. Many inexpensive shotguns were imported from Belgium for resale in this country, and bear those proofmarks. Many British-made shotguns carry Birmingham proofmarks, with London proofing mainly found on top-of-the-line British shotguns. Over the years, British proofmarks, both Birmingham and London, have changed as the Rules of Proof changed, and often the change in marks can be used to determine during what era a particular shotgun was made.

Unlike Britain and Europe where proofing of firearms is law, in the United States proofing is left to individual manufacturers. To be sure, American-made shotguns are plenty strong, almost to a fault, and following proofing are stamped with the individual manufacturer’s proofmark. The letter “P” superimposed on the bottom of a “W” surrounded by an oval is the familiar Winchester proofmark, Remington uses “REP” within a box, etc.

Proofing involves the firing of an overload that exceeds the service pressure of any given gauge and shell length by about one-third. The cartridges used, clearly marked Proof Loads and informally called “Blue Pills” in this country, are carefully controlled, and available only to firearm manufacturers.

—John M. Taylor

This “Questions & Answers” was featured in the November 2004 issue of American Rifleman. At time of publication, "Questions & Answers" was compiled by Staff, Ballistics Editor William C. Davis, Jr., and Contributing Editors: David Andrews, Hugh C. Birnbaum, Bruce N. Canfield, O. Reid Coffield, Charles Q. Cutshaw, Charles M. Fagg, Angus Laidlaw, Evan P. Marshall, Charles E. Petty, Robert B. Pomeranz, O.D., Jon R. Sundra, Jim Supica, A.W.F. Taylerson, John M. Taylor and John Treakle.

To subscribe to the magazine, visit NRA membership page here and select American Rifleman as your member magazine.


The Armed Citizen
The Armed Citizen

The Armed Citizen® Nov. 28, 2022

Read today's "The Armed Citizen" entry for real stories of law-abiding citizens, past and present, who used their firearms to save lives.

True Velocity: Re-Defining The ‘Metallic’ Cartridge

In developing its state-of-the-art centerfire rifle cases, True Velocity Ammunition has moved away from metal and placed polymer center stage. The result is a new self-contained cartridge that is lighter in weight, remarkably consistent from round to round and admirably accurate.

Preview: Federal Ammunition 100th Anniversary Book

As a tribute to the company’s first century in business, Federal Ammunition has released a special, limited-edition book that breaks down its history, decade by decade, across 244 pages.

Rifleman Q&A: 'Knuckleduster' Revolver

One NRA member writes to American Rifleman for answers about a peculiar so-called "knuckleduster" pepperbox chambered for .22 Short.

Preview: TangoDown Light Portal Front Sight

Due to their location on the gun, most front iron sights preclude the placement of a tactical light forward on a defensive carbine’s 12-o’clock rail, as they typically obstruct the light’s beam.

Holiday Gift Guide: Specialty Knives, Hand Axes & Multi-Tools

While smaller blades can be plenty helpful for everyday carry, sometimes bigger blades and tools are necessary. Here are a few larger specialty knives, hand axes, and multi-tools worth keeping in mind as the holiday season approaches.


Get the best of American Rifleman delivered to your inbox.