The 19th saw firearms evolve from flintlock muzzle loaders, using patched round ball and black powder, through to bolt action breech loaders with smokeless powders. As firearms development proceeded, so arms and ammunition needed assessing in comparative trials by the military. In the 1860s the National Rifle Association held competitive trials to determine which rifle would be used in the final stage of the Queen’s Prize at their Annual Rifle Meetings on Wimbledon Common. The system used to measure precision of rifled arms at this time was the “Figure of Merit”.