View source for M198 howitzer

==Ammunition types==
{{More citations needed section|date=January 2021}}
[[File: Royal Thai Army firing M198 howitzer.jpg|thumb|Royal Thai Army firing M198 howitzer]]

;High explosive (HE)
:([[M107 (projectile)|M-107]] NC/DC): Explosive [[Composition B]] material packed into a thick, internally scored shell which causes a large blast and sends razor-sharp fragments at extreme velocities ({{convert|5,000-6,000|m/s|ft/s|abbr=on}}). The kill zone has an approximate radius of {{convert|50|m|abbr=on}}, and the [[casualty radius]] is {{convert|100|m|abbr=on}}. The Marine Corps and US Army also uses the [[M795 projectile|M795]] High Explosive round.

;Rocket-assisted projectile (RAP)
: A high-explosive rocket-assisted (HERA) [[M549]] round with a greater range than the normal HE. The maximum range is {{convert|30.1|km|abbr=on}}.

;White phosphorus
: A base-ejecting projectile which can come in two versions: felt-wedge and standard. [[White phosphorus (weapon)|White phosphorus]] smoke is used to start fires, burn a target, or to create smoke which is useful in concealing the movements of friendly units.

;Illumination
: Illumination projectiles are base-ejecting rounds which deploy a bright parachute flare ideally {{convert|600|m|abbr=on}} above the ground and illuminate an area of approximately 1 grid square ({{convert|1|sqkm|abbr=on}}). Illumination rounds are often used in conjunction with HE rounds to illuminate the target area so that HE rounds can be fired more effectively. Illumination rounds can also be used during the daytime to mark targets for aircraft. The M485 illumination round burns for 120 seconds.

;[[Dual-Purpose Improved Conventional Munition]] (DPICM)
: A base-ejecting projectile that drops 88 [[cluster bomb|bomblets]] above a target. Each bomblet has a shaped-charge munition capable of penetrating 50 mm of solid steel as well as a fragmentation casing which is effective against infantry in the open. The DPICM round is effective against [[armoured warfare|armored vehicles]], even [[tank]]s (since the deck armor is usually the thinnest on the vehicle), and is also extremely useful against entrenched infantry in positions with overhead cover.

;[[Area Denial Artillery Munition System]] (ADAMS)
: An artillery round that releases anti-personnel mines. These mines eject tripwires to act as booby traps, and when triggered are launched upward before exploding. They are designed to self-destruct after a predetermined period.

;Remote Anti Armor Mine System (RAAMS)
: An artillery round that releases anti-armor mines, usually used along with ADAMS rounds to prevent the antitank mines from being removed. Designed to self-destruct after a predetermined period.

;[[M712 Copperhead|Copperhead]]
: An artillery launched guided high-explosive munition used for very precise targeting of high-value targets such as tanks and bunkers. No longer produced or used by the US military, it required the target to be designated with a laser designator system.

;[[Sense and Destroy ARMor]] (SADARM)
: An experimental munition fired in the general direction of an enemy vehicle. The shell activates at a certain point in time ejecting a parachute and then guides itself to the nearest vehicle.

;[[W48|XM454 AFAP (artillery fired atomic projectile)]] (W48)
: The XM454 AFAP (W48) nuclear artillery shell had a 155mm caliber and an explosive yield of only {{convert|72|tTNT|GJ}}. All units were retired from service in 1992.<ref name=W48History>{{cite report |date=January 1968 |title=History of the Mk48 Shell (U) SC-M-57-680 |url=https://osf.io/wsdxr/ |publisher=Sandia National Labs}}</ref><ref name=NukeArc>{{cite web |url=http://nuclearweaponarchive.org/Usa/Weapons/Allbombs.html |title=Complete List of All U.S. Nuclear Weapons |website=nuclearweaponarchive.org |access-date=18 November 2020}}</ref>