The M110 is a self-propelled howitzer of US origin. In the 1950’s the US Army required new heavy artillery for long range shelling and destruction of vital enemy positions. The new systems were to be mobile, be air transportable, use common parts and be quick in and out of action. A self propelled gun carriage would meet these requirements better than towed artillery. The Pacific Car and Foundry Company came up with a chassis that allowed for interchangeable 155mm, 175mm and 203mm cannon. Prototypes were developed as the T245, T235 and T236. After series of tests and design changes the T235 was accepted for US service as the M107 and the T236 as the M110 in 1961. With most armies the M110 was replaced with the MLRS, but many remained in US service for their nuclear capabilities.

The M107 and M110 both use the same chassis. The tracked chassis is made out of steel. The driver is seated on the left with the engine to his right. The armament is fitted to a large turntable with a limited traverse and a large spade is fitted at the rear to stabilize the vehicle during operation. The M107 is fitted with the very long 175mm M113 gun, while the M110 is fitted with the short 203mm M2A2 gun. Besides the driver the gun is operated by 12 other people. Of these 5 are carried on the weapon and the rest by the track M548 cargo carrier that also carries additional ammunition. Most M107 and M110 have been upgraded to the M110A2 standard.

The M107 has a range of 32.7 km with standard ammunition and was the longest ranging piece of artillery at the time of production. The M110 with its short barrel had a very limited 16.8 km range, requiring it to be closer to the front line and operate within the reach of enemy artillery. The M110A2 has a much improved range of up to 30 km. Due to the size and weight of their ammunition both systems have a low rate of fire and require a lot of crew to operate the weapon.

During travelling and in the firing position all members of the crew except for the driver are out in the open. This means that they are not protected from direct fire, shell splinters and NBC threats.

Compared to a towed gun of similar proportions the M107 and M110 are very quickly in and out of action. While being tracked vehicles they are also much more mobile than most towed artillery. Both models are fitted with the Detroit Diesel 8V71T 405 hp diesel engine.

The main user of the M107 and M110 was the United States. Both models were actively used in Vietnam. The M110 also saw operational use with UK and US forces during the First Gulf War. The M107 and M110 were also widely exported, mainly to Europe, the Middle East and Asia.