8 Inch Self Propelled

 

Specification from 1963

 

30 August 1963                                                                                                                                           TM 9-500                                                                                                                            

                                                                                                                                                                                    C 1

 

            CANNON, 8-INCH HOWITZER: M2A1E1; MOUNT, GUN-HOWITZER: M158;

                                                RAMMER AND LOADER ASSEMBLY ORD NO. 10898300;

                                                            MECHANISM, FIRING, CANNON: M35

 

                                                                            Secondary Item

 

                        Model                                                    Line item No.                                            Federal stock No.           

Cannon                     Mount            Mechanism

M2A1E1

M158                                                                                                              1025-863-5613

     M35                                                                                   1025-895-9182

 

General Specifications

 

            CANNON, 8-INCH HOWITZER: M2A1E1 with MOUNT, GUN-HOWITZER: M158, RAMMER AND LOADER ASSEMBLY ORD No. 10898300 AND MECHANISM, FIRING, CANNON: M35, provides the major armament for the HOWITZER, HEAVY, SELF-PROPELLED: 8-inch, M110 (T236E1).*

 

            The 8-inch howitzer cannon M2A1E1 consists of a barrel assembly screwed into an internal thread In a breech ring and locked in place by three screws.  The barrel assembly is of monobloc (one-piece) construction.  The chamber and bore are chrome-plated.  Bearings for support and alinement in the mount are provided by longitudinal rails attached to three hoops shrunk on the jacket.  The rear half of the breech ring is lined with a breech ring bushing to accommodate an interrupted screw-type breechblock and a bottom lug for connection to the recoil mechanism.

 

            The gun-howitzer mount M158 includes the recoil mechanism of the hydropneumatic variable recoil type, which controls the forces created by firing and checks the movement of the recoiling parts gradually, to avoid displacement of the vehicle, and also returns the recoiling parts into their original position.  The major components are the recoil, counterrecoil, and recuperator cylinders, contained In the gun cradle, and the replenisher cylinder.

 

            The rammer and loader assembly operates to lift a projectile from the rear or left side of the vehicle, position it for ramming, and ram it into the cannon chamber.  Hydraulic power for operation is obtained from the vehicle hydraulic system.  Operation can also be accomplished manually by means of handcranks.

 

            The firing mechanism is a percussion type and is operated manually by a lanyard.

 

Differences among models

 

Data plate location

 

Classification:

     Mount, M158                                                                                                                   Standard A (OTCM 37684)

     Cannon, M2A1E1

 

CHARACTERISTICS

Cannon:

            Weight:

Cannon complete                                                                                                              10,240 lb

Barrel assembly                                                                                                                   8,490 lb

Breech mechanism                                                                                                                         1,750 lb

Tipping parts                                                                                                                                   14,740 lb

Length:

Tube                                                                                                                                            16 ft, 10.5 in.

Cannon                                                                                                                                             17 ft, 9 in.

Rifling:

Length                                                                                                                                                  164.8 in.

Number of grooves                                                                                                                                   64                       

Bore:

In calibers                                                                                                                                                     25

Diameter                                                                                                                                                     8 in.

 

Breechblock                                                                                                    interrupted screw, stepped thread

 

Firing mechanism:

Type                                                                                                                                                percussion

Operation                                                                                                                        manual, by lanyard

Mount:

Weight                                                                                                                                                  4,500 lb

Recoil mechanism:

Weight (approx)                                                                                                                     3,925 lb

Type                                                                                                                          hydropneumatic

Number of recoil cylinders                                                                                                             1

Length of recoil:

Normal                                                                                         high elevation-28 to 30 in.

Maximum                                                                                      low elevation-68 to 70 in.

Equilibrator                                                                                                                       pneumatic

Type of recoil oil                                                                                FSN 9150-255-4443 (OHC)

Oil capacity                                                                                                                               15 gal

Oil reserve:

Replenisher                                                                                                                     2 pt

Recuperator                                                                                                                     2 pt

Elevation (max)                                                                                                                                   65 deg

Depression                                                                                                                                            0 deg

Turret traverse (right or left)                                                                                                                        30 deg

Traversing and elevating operation                                                                                   manual or hydraulic

 

AMMUNITION

 

Type                                                                                                                                                          HE, dummy

Loading                                                                                                                                                         separate

 

                                                                                 PERFORMANCE

 

Muzzle velocity                                                                                                                                           1,950 fps           

Range (maximum)                                                                                                                             16,930 meters

Allowable recoil (variable)                                                                                                                                            70 in. 

Rate of fire:                         

            Normal                                                                                                                                      1 rd per 2 min

            Maximum                                                                                                                                  1 rd per 1 min

 

Maximum number of rounds fired consecutively at max rate

Maximum powder pressure permitted            

Average accuracy life                                                                                                                                             rd           

 

                                                                                       EQUIPMENT

           

Sighting and Fire control:**

                       

            Installed on self-propelled howitzer M110 prior to issue:

MOUNT, TELESCOPE: direct fire, M138

                        MOUNT, TELESCOPE: panoramic, M137 (T186E3)

 

Boxed and stowed on self-propelled howitzer M110 prior to issue:

BINOCULAR: M17A1

FUZE SETTER: M26 and M27

                                   LIGHT INSTRUMENT: M52

PERISCOPE, TANK: M17

                        POST, AIMING: M1A2

QUADRANT, FIRE CONTROL: elevation, M15 (T23E2)

                        QUADRANT, FIRE CONTROL: gunner's, M1A1

REFLECTOR, AIMING POST: clear, M1                                   

REFLECTOR, AIMING POST: red, M2

SCALE. GRAPHICAL FIRING; M71                               

SCALE, GRAPHICAL FIRING: site, M72                                  

TELESCOPE, ELBOW: direct fire, M116C                              

TELESCOPE, PANORAMIC: M115 (T146)

Basic Issue Item: See TM 9-2300-216-10        

 

  INSTRUCTIONAL MATERIAL

 

PROJECTILE, 8-INCH. DUMMY: MK1

PROJECTILE, 8-INCH. DUMMY: M14

CHARGE, PROPEI,LING, 8-INCH, DUMMY: M4

PRIMER, PERCUSS10N INERT: MK2A4

Reference: TM 9-2300-216-10

 

*For characteristics and data, see item in section 23.

**For characteristics and data, see Item in sections 12, 14, 13, and 27.

 

Thanks to Lynden T. Couvillion (Couvi) for sending in the data.

Thanks to Charles E. Stephenson for preparing the information.

 

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