Conditions precedent to Proof.U.K.
Barrels for Arms of the First Class shall not be qualified for Proof until they shall be in a fit and proper State for setting up, and the Thread of the Screws sound and full.
Barrels for Arms of the Third Class shall not be qualified for Proof until they shall be in a fit and proper State for setting up, with the Squares set off looped, and the proper Breeches in the Thread of the Screws sound and full; and all Barrels lumped for percussioning shall be proved through the Nipple with the proper Pins or Plugs in.
Barrels for Arms of the Second and Fourth Classes:
For provisional Proof:—If of plain Metal, shall be bored and ground, having Plugs attached, with Touch-holes drilled in the Plugs of a Diameter not exceeding One Sixteenth of an Inch. Notches in the Plugs, instead of drilled Touch-holes, shall disqualify for Proof. If of twisted Metal, they shall be fine-bored, and struck up with proving Plugs attached, and Touch-holes drilled, as in the Case of plain Metal Barrels.
For definitive Proof:—The Barrels, whether of plain or twisted Metal, shall be smoothed in the finished State, with the Breeches in the percussioned State, Huts filed up, Bars of Barrels intended for Bar Locks properly filed up on the Top and Bottom Sides, the Top and Bottom Ribs of Double Barrels shall be rough struck up, Pipes, Loops, and Stoppers on the proper Breeches in the Thread of the Screws sound and full, and all Rifle Barrels shall be rifled.
Barrels for Breech-loading Arms, all which are subject to provisional Proof and to definitive Proof, shall receive the latter Proof after the Breech-loading Action is attached and complete.
Barrels for Revolving Arms shall have the Cylinders or Chambers with the Revolving Action attached and complete.