Urbanus Sartoris ( Sartorius) patented his breechloading system in 1817 ( Patent 4107) and 1819 ( improvements Patent 4336) around the time that Durs Egg was also producing his breechloading flintlock. Sartorius’s main contribution appears to have been the handle and opening mechanism, which seems to be ingenious and well made, but like most of the attempts to fit a breechloading mechanism into a flintlock or percussion gun, doomed to relative obscurity by the problems of gas leaks and fouling. Sartorius had sporting guns and rifles (total number unknown) made by Anthony Biven, and a number of the military carbines were made, although the total number is not known, Biven also made these. Biven was in business from 1822 to 1825 at No. 16 Regent Street London.