The invention provides equipment for measuring the inner bore of a small-
caliber barrel, and relates to the technical field of
barrel inner bore measurement. The small-
caliber body tube bore
measuring equipment comprises a control device and a
caliber measuring device, the caliber measuring device comprises a shell, a linear driving
assembly and a measuring head, and the linear driving
assembly is arranged in the shell; the measuring head comprises a shell, a central column and a plurality of measuring needles, the shell is detachably connected with the first end of the shell, and a plurality of mounting holes are formed in the end, away from the shell, of the shell; the central column is arranged in the shell. The plurality of probes are arranged in the mounting holes in a one-to-one correspondence manner. The central column is pushed by the linear driving
assembly to move in the housing along the axial direction, the moving distance of the central column is detected, and the probe is pushed by the
conical surface to extend out of the mounting hole along the radial direction so as to detect the inner
diameter of the bore of the body tube. The
conical surface is matched with the measuring needle to form a self-centering mechanism, so that the measuring head can be accurately positioned at the central position of the bore of the
barrel during measurement, and the
measurement precision is improved.