105mm Infantry Gun M130

The 105mm Infantry Gun M130 is, along with the 75mm Regimental Gun M121, the principle means of fire support afforded to American Infantry Regiments. Although it shares the carriage, gunshield, wheels and trail of the 75mm M121, it is a very different weapon - designed to fire high capacity explosive shells at a relatively low muzzle velocity along a steep parabolic arc, similar to a very light howitzer, and fufills a role akin to that of a mortar. Barring a hit on the thin armor above the engine compartment, its ability to destroy enemy armored vehicles is basically non-existent, though it is very devestating against entrenched enemy positions.

Design
Though it was designed to use many parts from the M121 and developed as part of the same program, the M130 performs the opposite role on the battlefield. Its breech mechanism is basically identical to its 75mm counterpart, albeit enlarged to accomodate 105mm ammunition, but it uses a shortened version of the barrel from the M101 light Field Howitzer. The gun has a 15 calibre (1.58 meter / 5.17 foot) barrel, most of which is housed inside of a rectangular sleeve integral to the single-piece recouperator / recoil tray mechanism (similar to the LeIG 18 above, although the M130's barrel is of a larger diameter and about 4 calibres longer). It is also fitted with a short square muzzle-brake.

Operational Employment
The 105mm Infantry Gun M130 essentially takes the place of heavy mortars like the old M2 4.2-inch Mortar of 1940s fame. It is a close-range indirect fire weapon, intended for breaking open fortified structures and assaulting dug-in positions. Prior to the introduction of the M65 Assault Gun, it was also conceived of as being used in direct support of infantry advances, but has since become obscelete in this role (and was never, practically speaking, very good for it). However, it excels as a sort of short-ranged light howitzer, raining high explosive shells down on enemy positions prior to and during an Infantry advance. In a pinch, it can also be brought to bear in a defensive direct fire role, preferably from dug in positions, although the low velocity of its projectiles makes hitting moving targets a tricky affair.

Production History
Designed: 1956

In service: 1957-Present

Manufacturer: United States Ordnance Department, Watervliet Arsenal

Specifications
Weight: 600 kg / 1,322.8

Barrel Length: 15 calibres

Shell: 105x372 R.

Calibre: 105mm / 4.2"

Breech: Semi-automatic vertical sliding block

Carriage: Split trail

Elevation: -5º to +70º

Traverse: 15º

Rate of fire: Up to 25 Rounds per Minute (15-16 sustained)

Effective Range: 3,500 meters

Maximum Range: ~5,000 meters