This paper presents a polarization detection method for the acquisition of the plot for the rotating speed of projectiles along the barrel of rifled guns.

0n the analysis of the method of gun- oral- sighting - device and target - boardmeasuring the deflecting angle between the axis of gun barrel and shooting plane, the paperpoints out the unreliability of the result and derlves calculating formula of the real deflecting an-gle.

During a widely research and investigate for a long period,much data about erosion and wear of rifled bores tank gun was accumulate.