The 81mm M29 Mortar - Original U.S. Army 8mm Training Film from 1962 in 4K HD

Published on January 7, 2026
Duration: 22:22

This U.S. Army training film from 1962 details the precise calibration and laying procedures for the M29 81mm mortar. It covers sight calibration using a boresight and aiming circle, establishing reference lines with aiming posts, and executing fire missions. The instruction emphasizes geometric principles for parallel laying and includes critical safety checks and misfire protocols, reflecting advanced military artillery techniques.

Quick Summary

The M29 81mm mortar sight calibration involves setting 800 mils elevation and zero deflection, using a boresight for alignment, and adjusting both the boresight and mortar sight. Laying the section uses an aiming circle for precise azimuth orientation, ensuring parallel barrels for accurate fire patterns.

Chapters

  1. 00:00Introduction: M29 Mortar Role
  2. 01:01Sight Calibration Fundamentals
  3. 01:55Boresight Components and Mounting
  4. 03:06Elevation Calibration Steps
  5. 04:50Deflection Calibration Steps
  6. 07:00Theory of Laying the Section
  7. 10:31Practical Laying Procedure
  8. 13:58Establishing Reference Lines
  9. 15:12Safety and Pre-Fire Checks
  10. 17:28Fire Mission Execution
  11. 18:47Misfire Procedures

Frequently Asked Questions

What are the key steps for calibrating the M29 81mm mortar sight?

Calibration involves setting the sight to 800 mils elevation and zero deflection. A boresight is mounted and cross-leveled on the barrel. The barrel is adjusted until the boresight's elevation vial is centered, then the mortar sight is adjusted. Finally, the elevation scale and micrometer are reset to 800 mils.

How is the M29 mortar section laid for accurate fire?

Laying the section ensures all mortar barrels are parallel using geometric principles. An aiming circle is set to a specific azimuth, and gunners align their sights to it, applying announced deflections to achieve the correct direction of fire.

What are the essential safety checks before firing the M29 mortar?

Before firing, crews must check for mask and overhead clearance. Mechanical checks include ensuring the barrel is locked to the base plate and bipod, and the spread chain is taut. The bore must also be swabbed.

What is the procedure for a misfire with the M29 mortar?

In case of a misfire, announce 'Misfire' and kick the barrel. After a one-minute wait and checking for heat, remove the sight, brace the bipod, and carefully tip the barrel to manually slide the round out.

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