Rules of Proof 6 (London)

A gun proof tested between 1904 and 1925 is examined here to illustrate the marks then used. It is a William Evans 12-bore with steel barrels.

This 12-bore is proofed under the Rules of Proof in force at the London Proof House from 1904 - 1925

‘Smokeless’ powders were now widely used to the Britain. So, guns marked with these stamps show ‘NITRO PROOF’ unless they have been proof tested for black powder only. The 'NP' with scimitar over mark was introduced to show Nitro Proof.

The stamps show:
‘V’ with crown over, which is the ‘View’ mark.
‘GP’ with crown over, which is the ‘Definitive Proof’ Mark
‘G’ in script with lion rampant over, which is the ‘Provisional Proof’ Mark
’12’ in a diamond indicates the chamber is 12-bore.
‘CHOKE’ indicates the muzzles of both barrels are choke bored.
‘1 1/8’ indicates the shot load in ounces.
’12’ indicates the actual bore size at nine inches from the breech (.729”)
‘NP’ with scimitar over is the London Nitro Proof mark, introduced for the first time in 1904, in tandem with the older 'NITRO PROOF' words.

The stamp on the tubes; '3020 is the gun's serial number, not a proof mark.