A Comprehensive Guide to the M79 Grenade Launcher

The M79 grenade launcher, a notable relic of Vietnam War history, is a firearm that stands out due to its unique design and specific utility. Designed and manufactured by Harrington and Richardson, the M79 establishes itself as a single-shot weapon that fires a 40mm grenade. Issued during the height of the Vietnam War, the M79 cannon was often humorously referred to as the "bloop gun" or "blooper." This guide will explore the details of the M79, from its design and functionality to its applications in combat.

Design and Functionality

The M79, officially adopted by the US forces in 1979, does not come from the world of ice-cream machines. Instead, it is a breech-loading, 40mm diameter single round weapon that resembles a short-barreled break-action shotgun. This distinctive weapon has been replaced in US service by grenade launchers mounted under rifle barrels. Exhibits in Vietnam War museums showcase its use in combat scenarios.

The M79 works much like a single-shot shotgun. It features a high-pressure chamber that bleeds gasses into a low-pressure chamber, resulting in a soft launch of the grenade. This design choice is driven by the nature of the grenade's payload, which necessitates a more moderate pressure system to control recoil and maintain accuracy.

Propulsion System

A nuanced look at the M79's propulsion mechanism reveals a high-low propellant system. The shell's cross-section shows a projectile on the right and an empty case beneath it. The key to this system is the reinforced pocket in the middle of the base, with holes leading to the main part of the case. On striking the primer, the high-pressure propellant ignites and expands through these holes, creating a moderate-pressure launch. This design allows for a lower pressure in the weapon casing and projectile, optimizing the weapon's performance for its intended use.

The majority of a 40mm round's volume often consists of the fuze, safety mechanisms, and detonator, meaning only a portion is dedicated to the actual payload. This highlights the necessity for controlled pressure and moderation in recoil, distinguishing the M79 from high-velocity firearms of similar caliber.

Operational Details

The M79 is a simple yet effective single-shot weapon. Upon discharge, the weapon has a self-cocking and self-safing mechanism. The safety is located on the tang for easy manipulation. As a single-shot weapon, it emphasizes manual loading and reloading. The stock of the M79 is an unusual shape, designed to accommodate both the sight and the need to fire at a higher angle, complicating shoulder alignment.

A distinctive feature of the M79 is the position of the buttstock, which is notably low on the shoulder, allowing for a more stable firing position. The rear ladder sight and the front sight at the barrel's end offer a unique aiming configuration designed to maximize the use of the grenade's high-arch trajectory.

The M79 can also be used in an improvisational manner to function like a mortar. Historical evidence suggests that this was achieved with a sling that marked the aiming point and a tangent sight, as described in the M15 rifle grenade sight appendix.

Historical Context and Usage

The M79's history is deeply rooted in the Vietnam War, where it played a crucial role in enabling soldiers to engage targets with more precise and destructive artillery. Its role in combat was significant, making it a valuable asset on the battlefield.

For those interested in delving deeper into the historical and technical details, referencing materials from the Vietnam War era and modern documentation on the M79 would be beneficial. This includes military manuals and contemporary accounts from soldiers and veterans who operated the M79 in combat.

Conclusion

The M79 grenade launcher stands as a testament to the innovative military engineering of the 20th century. Its simple yet effective design and unique operational characteristics make it a fascinating subject for any student of military history or enthusiast of arms and ammunition.

Given its historical significance and unique features, the M79 continues to pique the interest of historians, collectors, and armory enthusiasts. Its study and understanding can provide valuable insights into the evolution of military technology and the tactics employed in modern warfare.