The 90 mm Recoilless Rifle, M67, was a "lightweight [35 lbs], air-cooled, single shot, breech loaded
weapon"    that could be fired from the ground or from the shoulder.  It was a 53" long direct fire
weapon that fired a  9 1/4 lb. HEAT (High Explosive Anti-Tank) round to an approximate maximum
effective range of 450 m.  The sight with a reticle pattern graduated from 0 to 800 m. is visible on top
of the tube.  Dennis Linn and Ray Tyndall pose in this 1970 photo taken near Van Thien.

Standard ammunition for the 90 mm RR was the HEAT, M371E1 round with a fin stabilized, shaped
charge projectile that traveled at 700 fps.  A piezoelectric crystal in the M503 fuse in the protruding
nose spike of the round generated electrical energy which detonated the shaped charge filler at exactly
the right "stand-off" distance from the target.  When the round was fired, the frangible base of the round
broke into small particles which were blown out of openings in the breech by the propellant gases. The
fan shaped backblast area, a 55 m. wide area which extended 28 m. to the rear of the weapon, was a
dangerous place to be when the weapon was fired.  Ray Tyndall demonstrates the proper prone firing
position while Ray Mendez inserts a round into the breech prior to test firing the weapon in 1970 near
Van Thien, Vietnam.

[Above photos provided by Ray Tyndall, 3/B/1-6 Inf 1970-71;  technical information and photos below
from a US Army Infantry School pamphlet, 1968]

LAW - Light Antitank Weapon - 66 mm HEAT Rocket, M72 consists of a  self-contained fin stabilized
20" round (2.2 lb) packed in a telescoping (35"), expendable launcher tube (2.5 lb).  The warhead
contains 2/3 lb. of octol explosive in a shaped charge that traveled to the target at 475 fps.  Maximum
effective range was 200 m.  Once the rear cover retaining pin was removed, and the cover and sling
assembly were released, the launcher could be extended by pulling on the bail handle on the rear.  After
removing the rear safety pin, placing the launcher on the shoulder, and pushing forward on the trigger
release, the weapon could be fired by pressing down on the trigger bar.  A fan shaped danger area 15 m.
deep and 8 m. wide extended behind the launcher.

The front sight for the M72 was clear plastic with a reticle pattern graduated from 100 to 325 m with a
15 mph lead index on either side.  The rear sight was fixed with two peep holes for different
temperatures.

Although the M72 LAW supposedly was capable of defeating the heaviest known tank armor, this was
true only if the round impacted perpendicular to the target.  It was used in Vietnam against enemy
bunkers and fortified positions with great success.

Select additional photos from the index at left or link to the 1st Bn 6th Inf  Home Page.