We feel that our customers should have the comfort of knowing that the gun they are purchasing has been reproved after restoration has been completed. Therefore Heritage Guns almost invariably reproofs its shotguns before sale although the reproof may not be strictly necessary from a legal perspective,
Usually we repoof to 2 ¾" (70mm) chambers to give the shooter more flexibility with ammunition but where the chamber length is significant to the type or style of the gun we will either leave the gun with its original proof or reproof to a more appropriate chamber length.

Some Information on English Proof

For those uninitiated into the traditions of Proof and Reproof, we will attempt to give some insight into this essential and historic practice.

The British Proof Authority is composed of The Worshipful Company of Gunmakers of the City of London and The Guardians of the Birmingham Proof House. Do not let their anachronistic sounding titles fool you, these august organisations are very much in the business of modern gunmaking and by law every sporting gun in the United Kingdom must at some point have passed through their skilled hands before being sold.

As an introduction, we can do no better than to quote from the 5th Edition of 'Notes On The Proof Of Shotguns And Other Small Arms' issued by the British Proof Authorities.

'Proof is the compulsory and statutory testing of every new shotgun or other small arm before sale to ensure, so far as is practicable, its safety in the hands of the user. Reproof is the similar testing of a small arm which has previously been proved. Both necessarily involve the firing through the barrel of a considerably heavier load than is customary in the sporting field, thereby setting up pressure and stress on the barrel and action much in excess of the pressure generated by standard load cartridges. Such pressure should and is intended to, disclose weakness in guns, whether new or used, for it is preferable that weakness by found at a Proof House rather than in the field, where personal injury may result.'

The Notes go on to explain the history of the Proof Laws and Houses and under the heading 'Reproof' it gives the following information.

'Reproof, or the further test of a gun after its original proof, may be necessary for a variety of reasons, of which the main ones are set out below:
Indications of weakness in action or barrel, including cracks, pitting, bulges, dents or failure of the brazing of the lump.
Potential weakening, such as by conversion to ejector, repair of the action or barrel by welding, electrolytic deposit of hard chrome or other metal in the barrel.
Enlargement of the internal diameter of the barrel, or lengthening of the chamber, so that it no longer conforms with existing proof marks.
Replacement of action, barrel, barrel lug or extension.
Fitting of any attachment, such as a variable choke, which must withstand the pressure of firing.
Present inadequacy of earlier proof. Black Powder proved guns, most commonly proved over 90 years ago, may not be safe for use with smokeless cartridges and require reproof for nitro powders.'

Proof law, marks and measurements are a complicated science all in themselves and a full study of the Notes mentioned above, available from either Proof House, should be undertaken if a reasonable understanding is required.
We are delighted to try and help with any queries our customers may have on specific proof marks on either our guns or their own. However, without having the gun in our hands it is often very difficult to supply definitive information. We therefore recommend obtaining top quality digital photos of all marks on action or barrel flats or the barrels themselves and sending them to us along with your enquiry.
As to whether a gun is in or out of proof, this not only requires an examination of the features mentioned above but also an accurate measurement of the interior bore diameter, 9" from the breech face. Without the correct tools this is very difficult and we would encourage owners to seek out a qualified gunsmith with experience of English Proof law rather than attempt to assess proof from afar.