Arsenal | M19 60 mm Mortar

The 1st and 2nd platoons of B Company, 9th Marine Regiment, attacked North Vietnamese Army positions on Hill 861 near Khe Sanh on April 24, 1967, and came under heavy fire as they moved into position. The Americans responded by deploying the company’s 60 mm mortars, but the difficult terrain complicated mortar placement. Lance Cpl. Dana Darnell placed his helmet between his legs and set his mortar tube’s base upon it, using his hands to steady the weapon. The Marine maintained a steady rain of fire on the enemy throughout the engagement, pausing only to gather more ammunition. Darnell, killed in action two days later, was awarded the Navy Cross for his actions on April 24.

His M19 60 mm mortar had been designed to replace the M2 mortar of World War II and fired the same ammunition. Rejected by the Army, the M19 was favored by the Marines—even though 10 pounds heavier, shorter-ranged and less accurate than the M2—because it had sights and a manual trigger that enabled the crew to aim it at a specific target for “direct fire” and not just lob shells at an unseen target using “indirect fire.”

The M19 had an M5 rectangular base plate and a bipod that supported the muzzle-loaded smoothbore barrel. Crewmen could anchor the mortar tube in a helmet if a base plate wasn’t available. The sight was an M4 collimator sight, which allows the viewer to see an illuminated aiming point aligned with the weapon, regardless of eye position. The mortar was fired manually using a “firing lever” trigger for direct fire at low angles of elevation. When the tube elevation exceeded 60 degrees, the projectile was dropped into the tube and fired when its ignition cartridge struck the firing pin. Range was set by adjusting the tube’s elevation and clipping “booster charges” to the tail fin—four for maximum range.

The M19 was a company-level weapon for U.S. and South Vietnamese marines, filling the indirect-fire gap between the M79 grenade launcher and the 81 mm battalion-level mortars. Never as popular as its M2 predecessor, the M19 gave way to the M224 60 mm mortar by the early 1980s.