Mortar (weapon)
Ammunition

Ammunition for mortars generally comes in two main varieties: fin-stabilised and spin-stabilised. Examples of the former have short fins on their posterior portion, which control the path of the bomb in flight. Spin-stabilised mortar bombs rotate as they travel along and leave the mortar tube, which stabilises them in much the same way as a rifle bullet. Both types of rounds can be either illumination (infrared or visible illumination), smoke, high explosive, and training rounds. Mortar bombs are often referred to, incorrectly, as "mortars".

Operators may fire spin-stabilised rounds from either a smoothbore or a rifled barrel. Rifled mortars are more accurate but slower to load. Since mortars are generally muzzle-loaded, mortar bombs for rifled barrels usually have a pre-engraved band, called an obturator, that engages with the rifling of the barrel. Exceptions to this were the U.S. M2 4.2-inch mortar and M30 mortar, whose ammunition had a sub-calibre expandable ring that enlarged when fired. This allows the projectile to slide down the barrel freely but grip the rifling when fired. The system resembles the Minié ball for muzzle-loading rifles. For extra range, propellant rings (augmentation charges) are attached to the bomb's fins. The rings are usually easy to remove, because they have a major influence on the speed and thus the range of the bomb. Some mortar rounds can be fired without any augmentation charges, e.g., the 81 mm L16 mortar.
punctuation:no_comma, language:response_language[Dutch], keywords:forbidden_words