Source: H.L. Blackmore. British Military Firearms, 1650 to 1850. London, 1961.
**The quotation to follow was originally made by John Marshall who was the Clerk and Paymaster of the Ordinance of Birmingham in 1824. His words were captured at a Court of Enquiry;
"The Locks were brought in a soft state, were gauged and examined in all their particular parts, the springs were ascertained to be of a proper strength, and the face of the hammer was tried with a file to see whether it was steeled - if the lock was proper and serviceable, the viewer affixed his mark on the inside of it, and the broad arrow on the outside. -It was then received into store and afterwards given out to the contractors for setting up, who engraved and case-hardened it - this applies to the India Pattern lock which was not taken to pieces, but only the tumbler pin taken out - the Land Service pattern locks were all taken to pieces when the musquet was brought to the finishing viewer he inspected the Lock."