gun, for instance, is normally used at an effective range of 1,100 m (1,200 yards), compared to its maximum range of 3,725 m (4,074 yards). The mitrailleuse, by contrast, was often used at the outer edges of its range and without the benefit of optical range finding equipment. These deficiencies in the operational usage of the Reffye mitrailleuse proved disastrous in the Franco-Prussian War. Use in war Franco-Prussian War (1870–71) Mitrailleuses were used in many of the major engagements of the Franco-Prussian War (1870–71), but their small numbers greatly restricted their effectiveness. Their flawed usage was a serious problem on the battlefield. While the mitrailleuses were inherently accurate, in a ballistic sense, they were often unable to zero in on targets quickly enough at great distances. Individual 25 round salvos were also too tightly grouped and lacked lateral dispersion. To make matters worse, the complex firing mechanism was vulnerable to damage at the hands of inexperienced crews. Fouling of the mechanism by black powder combustion residues and thus difficulties in closing the breech were reported as a problem after prolonged firings. In a few instances where the Reffye mitrailleuses were put to good use, they showed that they could have a significant impact. Captain Barbe's mitrailleuse battery at the Battle of Gravelotte devastated massed Prussian infantry when they had quickly found the range on their targets, contributing to the exceptionally high Prussian death toll in that battle. Other examples of effective mitrailleuse fire have also been described for the battle of Mars-la-Tour. For the most part, however, mitrailleuses proved ineffective. It was concluded after the war that Chassepot rifle fire had caused a far greater number of Prussian casualties than the Reffye mitrailleuses. However, about 100,000 Chassepot rifles were engaged in combat in contrast with fewer than 200 Reffye mitrailleuses used in battle at any given time. The Prussians and foreign observers were not impressed by the performance of the mitrailleuse. In the case of the Prussians, their views were undoubtedly coloured by propaganda. They had very few machine guns or volley guns of their own and, not least for reasons of maintaining morale in the face of a new weapon technology, they scorned the effectiveness of the mitrailleuse. They nonetheless saw the weapon as a threat and Prussian artillery always made it a priority to engage and destroy mitrailleuse batteries. The weapon's characteristic "snarling rasp" does appear to have