Proof Mark (noun)

Photo of proof marks on a Winchester Model 62A rifle.
Photo of proof marks on a Winchester Model 62A rifle. Photo © Russ Chastain


A proof mark is a symbol and/or series of letters and/or numbers stamped into a firearm or gun. It may occur on the barrel, cylinder, frame, receiver, or all of the above. The purpose of the mark is to indicate that the part in question has been tested with a proof load, and is thus safe to fire with standard ammunition loads.

Many countries have national proof houses, where every gun made in that country must be proofed.

Those that pass the proof test are marked with proof marks, and then may be exported or otherwise sold to consumers.

The United States of America has no national proof house, so guns are routinely proofed by many (but not all) manufacturers, and are generally marked with proof marks after passing the proof test.


The Winchester Model 62A has proof marks on the rear end of the barrel, and the front end of the receiver.

- Russ Chastain

Glossary Index

mla apa chicago
Your Citation
Chastain, Russ. "Proof Mark (noun)." ThoughtCo, Mar. 3, 2017, Chastain, Russ. (2017, March 3). Proof Mark (noun). Retrieved from Chastain, Russ. "Proof Mark (noun)." ThoughtCo. (accessed November 19, 2017).