Secret howitzer
[1][2] Shuvalov's gun had an unusual, oval bore, which was designed to facilitate shot dispersal while firing canisters and therefore to increase the beaten zone.[2] The guns proved quite effective in action during Seven Years' War, especially at Gross-Jägersdorf, but some were lost to Prussians at Zorndorf (thus revealing their secret).[1] Originally used by the Observation Corps and howitzer units, in 1759 they were attached to the infantry regiments; however, next year the decision was reversed.[3] In practice the shot dispersal was hardly better than of ordinary guns, reloading was slower, and the inability of the cannon to fire any other projectiles hampered its effectiveness.[2] Slow reloading was the reason given for the loss of 17 of these guns at Zorndorf, where they were overrun by cavalry before they could fire a second shot.