eldror

摘要

Existence of cracks through the liner of a gun barrel is determined by sizing the outer tube of the barrel to expand and jam in the recoil jacket in response to pressure between the liner and the tube; or by providing electrical conductors between the tube and the liner which change their electrical characteristics when cracks form; or by permitting powder gases to leak through small openings in the tube as an indication of failure; or by a combination of these methods.