Replacing the M3 Optical Borescope and Pullover Gauge

Zistos GBIS consolidates the M3 optical borescope and the pull-over gauge into one digital workflow. The Large system images the bore with HD cameras and, with the optional Bore Measurement Kit, measures diameter to ±0.001 in (0.04 mm), with data recorded onto each image.

Maintainers have long inspected gun tubes with two separate tools: an optical borescope to look at the bore surface, and a pull-over gauge to measure it. Zistos GBIS brings both jobs into one documented, digital workflow.

Two tools, one workflow

The Zistos GBIS Large system pairs a wide-angle forward camera with a magnified side camera of up to 16 MP. With the optional Bore Measurement Kit, a self-centering 3-point head spans the rifling and records a true diameter reading to ±0.001 in (0.04 mm).

What changes for the maintainer

• See the bore surface: erosion, pitting and cracks, imaged and on screen.
• Measure to spec: internal diameter against tolerance, not a subjective call.
• Document for the record: settings, depth, angle and measurement are written onto each image, and readings export to CSV.

The four step procedure

• Assemble and insert: fit centering rings, attach poles and handle, insert the camera.
• Locate artifacts: scan with the forward camera and note the orientation angle.
• Measure: attach the calibrated head and record diameter against tolerance.
• Record: capture annotated images and export measurement data.

Inspections follow the applicable government technical manuals. See the full system on the Zistos GBIS page and the GBIS Large system.

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