TRW Low Maintenance Rifle

The TRW Low Maintenance Rifle or LMR was a proposed insurgency weapon designed by TRW Inc. (formerly Thompson Ramo Wooldridge) of the United States during the Vietnam War. The intent was to produce an easy-to-use and operate firearm which could be disseminated to insurgent forces supporting the United States' military interests. The design utilized the same 5.56×45mm NATO ammunition and STANAG magazines as the M16 rifle. It would have been equipped with the M6 bayonet along with its M8A1 scabbard.

TypeFull-automatic fire only insurgency assault rifle

Placeoforigin United States

DesignerDonald A. Stoehr (1927-2011)^[1]

DesignedFebruary 1971^[2]

Quick facts Type, Place of origin ...

TRW Low Maintenance Rifle
The TRW LMR. Minor differences exist in the stock, handguard, and sights given the various prototypes made.
Type	Full-automatic fire only insurgency assault rifle
Place of origin	United States
Production history
Designer	Donald A. Stoehr (1927-2011)[1]
Designed	February 1971[2]
Manufacturer	TRW Systems Group
Unit cost	Specified cost of less than $130 (1971),[3]
Produced	1971—1973
No. built	fewer than 10.
Specifications
Mass	Unloaded: 3.30 kg (7.3 lb)[4] Loaded: 3.64 kg (8.0 lb)[4]
Length	871 mm (34.3 in)[4]
Barrel length	493 mm (19.4 in)[5]
Cartridge	5.56×45mm NATO
Action	Roller locked open bolt gas-operated long-stroke piston
Rate of fire	450 RPM Cyclic[4]
Muzzle velocity	3,248 ft/s (990 m/s)[4][5]
Effective firing range	460 metres (1,510 ft)[4]
Maximum firing range	2,425 metres (7,956 ft)[5]
Feed system	20, 30-Round STANAG magazine[4]
Sights	Rear: Two-position flip aperture Front: Adjustable post

Close

Development began in 1971, and ceased in 1973 with the weapon never having been fielded.