Gun Proof at the London Proof House

The world's oldest Proof House, continuously testing military and civilian firearms for safety and conformity for nearly 400 years.

The Historic Home of Gun Proof

Founded by Royal Charter in 1637, during the reign of King Charles I, the London Proof House in Whitechapel is the time-honoured home of British gun proof. For almost four centuries, its role has been to test firearms for safety, ensuring every gun in the UK meets strict quality standards.

Why Proof Exists

Proof is the test firing of firearms using precision built and controlled proof ammunition. Proof ammunition when fired generates pressures greater than maximum service ammunition pressure. This extra pressure stresses the firearm so that any failure modes are identified. Once a firearm is proved and inspected to confirm safety and integrity, the Crowned GP London mark used for almost 400 years is applied to the firearm. This rigorous and regulatory process ensures public safety, protects shooters, prevents unsafe weapons entering the market, and underpins trust across the British gun trade.

The Gun Barrel Proof Act

Under the Gun Barrel Proof Acts, especially the 1868 Act, it is illegal to sell or transfer an unproved gun in the UK. The law requires all new, imported, materially altered or repaired firearms to undergo proof testing, making safety a legal obligation, not an option.

Proof and the C.I.P.

The Proof House is a member of the C.I.P. (Commission Internationale Permanente), which sets international proof standards. Thanks to this, London-proofed firearms are recognised abroad, supporting global trade while upholding safety.

The Building and Its Legacy

The Grade II listed Georgian Proof House, with unique architectural features has witnessed firearm proving from flintlocks to modern weapons for, civilian, uniformed services and military. Its proof bays, populated with the latest state-of-the-art proving fixtures and bullet catchers, are located within another ancient building. Our collection of historic buildings still serve the same purpose today, the proving of firearms, ensuring public safety while preserving a tradition that defines British gun making.

Gun Proof Services