In 1865, brothers William and George Miller of Meriden CT patented a system to convert percussion muskets to use the new Rimfire ammunition that was becoming available. Between 1865 and 1867, the local Meridan Manufacturing Company converted 2,000 surplus US Model 1861 muskets (mostly made by Parker & Snow) to the Miller system, using .58 Rimfire ammunition. The US military tested one of these conversions in 1867, and found it to suffer from some gas leakage and about a 3% misfire rate. There was no further Army interest, although the New York and Maryland state militias did both purchase small numbers of the guns.