LAUNCHER, ROCKET: 3.5-INCH, M20, M20BI, M20A1, M20A1B1, WE

M2OA1BI .
M2OAI H1

Major Item
Model Line item No. Federal stock No.
M20 ........................4-20800-10 1055-675-0064
M20A1 .....................4-20800-20 1055-840-1841
M20A1B1 ...................4-20800-30 1055-840.1842
M20BI ................ . .... 4-20800-40 1055.591.0217
General
LAUNCHER. ROCKET: 3.5-inch, M20, M20AI, M20A1B1; or M201,i, w/e, is a two-piece, smooth-bore, breech-loading, shoulder weapon of the open-tube type. They are used to launch 3.5-inch rockets and high explosive rockets against ground targets and can be fired from the standing, kneeling, sitting, or prone positions. The rockets are fired electrically by a magneto-type firing mechanism in the trigger grip. These weapons have very little recoil since the propulsion of the rocket Is accomplished by the jet action of the propellant powder in the stabilizer tube of the rocket and does not depend upon gas pressure built up inside the launcher tube. Each launcher Is issued with an optical type reflecting sight having a bellows-type rubber eyepiece. When firing the launcher, it is essential that no personnel or flammable material be directly behind the launcher, within a distance of 25 yards, to prevent being burned by the propellant. The danger zone Is a triangular area with a base and a height of 25 yards. When firing from the prone position, the operator's body should be at an angle of at least 45' from the direction of fire so as to avoid being burned by the propellant. On launchers of early manufacture, a bipod and monopod were provided to permit firing from the prone position. However, launchers of present manufacture do not Include these components. On some of the launchers of early manufacture, the monopod was modified by the removal of its extending leg (see launcher M20A1 illustrated).
Differences among models
The barrels of the M20 and M20A1 are manufactured from aluminum tube stock and the component parts fastened to the barrels by means of screws. The barrels of the M20A1B1 and M20BI are aluminum castings and many of the component parts of the barrel are cast integral with the barrel effecting a slight saving in overall weight. With the addition of a new contactor latch, the launcher M20 becomes the launcher M20A1 and by the same addition the launcher M20B1 becomes the launcher M20A1BI. Iii addition, there are minor differences which are apparent when the illustrations are compared.
Data plat. location
The model and serial numbers are stamped at the rear end of the rear barrel of the launcher M20 and are cast on top of the rear barrel of launcher M20131.
Classification: Standard A (OTCM 36841).
CHARACTERISTICS
Weight of launcher (approx):
M20 or M20A1 (w/o biped and monopod) ...............18 lb M20B1 or M20A1B1 (w/o bipod and monopod) ..........12 lb Length overall:
Assembled for firing ..............................5 ft. % in.
Assembled for carrying (approx) ..................2 ft, 6 in.
Type of firing mechanism ................................electrical
AMMUNITION
Types ..................................HEAT, WP, and practice
PERFORMANCE
Muzzle velocity:
HEAT (3135) .......................................485 fps
HEAT (M28A2) .....................................817 fps
Range:
HEAT (M85) ......................................1,300 yd
HEAT (M28A2) .....................................945 yd
Rate of fire ..........................................
EQUIPMENT
Sighting and fire control:*
The following, which are part of the launcher, are used for sighting:
SIGHT: reflecting. easy (ORD No. 7162947) (M20A1 or M2OA1B1).
SIGHT: reflecting, nosy (ORI) No. 7141999) (M20 or M2OB1).
SIGHT: rocket launcher. M39 (FSN 1240-346-8684) (replacement for above sights).
Basic Issue Items: See OB,D 7 SNL B-42.
INSTRUCTIONAL MATERIAL
GRAPHIC TRAINING AID AND DEVICES: See DA Pam 310-5. * For characteristics and data, see item in section 14.
STORAGE AND SHIPMENT DATA
Within and Outside Continental United States
Shipped 4 launchers per wood le,.'(VCI PHCk)
Length----------------------------------------------:4 ft. % in.
Width:
M20 or M20BI -------------------------------2 ft. 841 in.
M2OAI or M20AIBI --------------------------2 ft, lS'/4 in.
height---------------------------------------------1 ft. 4 in.
Volume:
M20 or M2081 ------------------------------------11.0 cu ft
M201t1 or M20AIHI --------------------------------11.3 CU ft
Cross weight:
1120 or M20131 ------------------------------------------135 lb
M20AI or M20AII31 -----------------------------------10 lb
Shiptons ----------------------------------------------------0.2$
Reference.: TM 9-2002, TM 9-2205, TM 9-1055-201-12P, TM 91055-201-85P, FM 28-82, TM 9-500

Includes stand