[Arkie2]

Mortars are used as supporting weapons in every modern army. Especially in a hilly area this indirect fire weapon with its high mobility often is the only applicable artillery.

A moden mortar bomb is stabilized in flight by means of tail fins. The high trajectory results in a high angle of attack and makes mortars more suitable than artillery for use in built-up areas or mountains; mortars are not as accurate, however. Artillery also differs in firing a projectile through a rifled barrel, thus creating greater muzzle velocity.

[U S Army EOD]

Mortars are just another form of artillery. The 4.2" mortar has a rifled barrel and the projo no tail fins, it is spin stabilized. There are also some mortars that are actually breach loaded also. The modern definition is based on barrel length vs projo diameter and the basic trajectory of the shell. Mortars, howitzers, cannons, and guns are all forms of artillery. This includes AAA.

Used to be in the American army, all the mortars were in heavy weapons companies with the 75's, 105's, 155's, 8", and 240's being in units designated as artillery units. If you get a chance, go to APG, Maryland. They have an experimental mortar up there called Little David. If I remember right, this monster was in excess of 700mm. It was about twice the size of a 16" shell.

The Germans used a 430mm mortar during WWI which was in an artillery unit. They also used one they called Thor in WWII that was some enormous size.