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
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
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.