The first guns built used quoins for changing the elevation, but in 1753–1758 turnscrews were introduced. Originally they had cylindrical powder chambers like howitzers, but guns produced after 1758 had conical chambers like licornes. 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).