For most of the 18th century, muskets ordered from Birmingham contractors by the Ordnance Board were either proof tested to the Tower standard, within the grounds of the gun maker by an Ordnance Board inspector, or taken to London to be proved.1
In 1755, Board of Ordnance viewers were stationed at Birmingham to gauge and view barrels made by contractors for the Ordnance. Those that passed the test were then sent to London for proof. In 1777, with the increase in demand caused by the American War of Independence, the Ordnance in Birmingham established a warehouse to try to ease the selection process, but this caused the Ordnance viewers to become even more discriminating, which made the process even slower. Those barrels that passed selection faced a nine-day journey to London by road and canal and the contractor had to bear the cost of transportation as well as the expense of any rejected barrels.4
Soon after the outbreak of the Napoleonic wars this system was deemed unacceptable as more efficient and less time consuming processing methods were needed.
In 1796 the Board of Ordnance decided that the only way to overcome the situation was to build a proof house at Birmingham.4 The Government purchased land between the Birmingham-Fazeley canal, Walmer Lane (later Newtown Row) and Bagot Street, Birmingham. 2 A state-owned proofing establishment was erected on the site, with the main entrance in Bagot Street.4
While the Ordnance proof house was being built, an agreement was made with the gunmakers Galton, Ketland and Walker, Whately, Grice and Blair for their barrels to be proved at their own proof houses by the Ordnance viewers. 4
The Bagot Street Ordnance proof house opened in 1798 for the purpose of viewing and stamping all new government arms with a ‘Tower’ mark.5
The first Bagot Street proving house, ‘the explosions of which were very terrific to strangers’, 3 was replaced in 1808 by a larger one on the same plot but ‘at a greater distance from the view rooms’. A new View Room was built in 1811.4