Attached to the right of the screw is the traversing handwheel. The equipment is placed out the same as for the gunner's examination (Chapter 9). He moves the mortar until the vertical line of the sight is aligned approximately on the aiming post. Increments removed from cartridges before firing should be placed in a metal or wooden container located outside the firing vehicle/position at least 25 meters away. The fuze consists of a brass head, body assembly, and expelling charge. Then it is removed from the bipod and laid horizontally on the ground at the dud pit until it can be turned over to ordnance personnel. 81MM M252A1. a. The leg-locking handwheel must then be tightened, ensuring the teeth are correctly meshed. It is painted white with black markings. TM - Technical Manuals (Range 9) TM - Technical Manuals (Range 10) TM - Technical Manuals (Range 11-4) TM - Technical Manuals (Range 11-5) . M252 81mm Mortars The M252 81mm medium extended range mortar (see diagram below) is a crew-served, smooth bore, muzzle loaded, high angle of fire weapon system. The squad leader notifies the FDC of the minimum mask clearance elevation. The 81mm mortar rounds use Red Phosphorus as the smoke generating agent. . Referring and realigning aiming posts ensure that all mortars are set on the same data. The cartridge is painted light green and has red markings and one narrow yellow band. The M301A3 cartridge has a cylindrical body that contains an illuminating candle and parachute assembly. .30, BROWNING, M1919A4 AND M2 (HEAVY BARREL), .30, M2 (REPRINTED W/BASIC INCL C1) (S&I BY PROP SEE DETAILS, FOOTNOTES), GUN, MACHINE: CAL. When the gunner is satisfied with his sight picture he announces, "Up.". The gunner can depress the barrel, if necessary, to provide easier access to the firing pin. The first ammunition bearer puts both hands on the cooling fins under the barrel and slowly lifts the barrel until it is horizontal. At this command, the squad proceeds as follows: a. Upon completion of any bipod movement on the barrel, the gunner ensures that the firing pin recess is facing upward. He maintains the ammunition for firing and provides local security for the mortar position. FT 81-AI-3 Firing Tables Mortar, 81mm: M28A1 and M29 Mortar 81mm Self propelled M125A1 and M125 Carrier, 81mm Mortar Tracked XM755 SQUAD AND SECTION ORGANIZATION AND DUTIES, Each member of the infantry mortar squad has principle duties and responsibilities. He places the sight case and aiming posts to the left front of the mortar position. b. The tabulated data of the 81-mm mortar, M252, are shown in Table 4-1. The types of fuzes described in this paragraph are point detonating, proximity, mechanical time, multioption, and dummy. He makes large deflection shifts by shifting the bipod assembly and keeps the bubbles level during firing. M120/M121 120 mm Mortar. Red phosphorus/white phosphorus is used for screening, producing casualties, creating incendiary effects, and signaling. He ensures that the firing pin recess is facing upwards. The safety wire must be removed before firing. The following safety checks must be enforced before firing the mortar. high-explosive bomb at a range of about three miles. c. The first ammunition bearer checks the barrel and ensures that--. See Chapter 3, paragraph 3-14 for a detailed discussion of malfunctions. This action breaks an internal sheet pin and internal wire, thereby disabling the proximity function. In any case, the gunner must ensure that the cartridge does not strike an obstacle. c. The assistant gunner lifts the bipod and stands it on its elevating leg so that the elevating handwheel is to the rear and the plain leg is to the front. He has the duty of preparing the ammunition and passing it to the assistant gunner. Finally, the assistant gunner loosens the leg-locking handwheel, presses the spring-loaded locating catch, and raises the plain leg behind the buffer cylinders until it touches the traversing handwheel. c. Mechanical Time. b. Normally, it can be moved by hand, although this may be difficult to do if the mortar is moved through a large arc. 1:4 For the 81MM Mortar System: X NSN (LIN): 1015-01-441-3113 : STAFF SECTION, CLEANING, ARTILLERY 1:4: Following the arm-and-hand signals of the gunner (who is looking through the sight unit), he moves the far aiming post so that the gunner obtains an aligned sight picture. The cartridges are painted olive drab with yellow markings. The gunner removes the sight and places it in the case with 3200 deflection and 0800 elevation indexed. b. All rounds are colored according to their type. Types of rounds, classification, and characteristics for the 81-mm mortar, M252. f. If the above procedure fails to remove the misfire, the barrel must be kept horizontal. He then checks the sight picture to ensure he is within 20 mils of a proper sight picture. The fuze is screwed into the cartridge body, and it is seated and secured using an M18 wrench. Each round is stenciled with the ammunition lot number, type of round, type of filler, and caliber. b. Standard A ammunition for the M29A1 mortar is Standard B for the M252 mortar (, Light green Yellow band with red markings. If the barrel is cool enough to handle, the crew removes the round as described below. After the 30-minute waiting period, the dud is still dangerous but can be approached and removed carefully or destroyed in place by qualified disposal personnel. This is the inert PD fuze type "IR-81" used by the Italians for their 81mm mortar rounds during WWII. Propelling charges are covered or protected from dampness or heat. He tightens the leg-locking handwheel (ensuring the teeth are correctly meshed) and fastens the securing strap over the arm and around the buffers. The cartridges are returned to their original containers. The cannon assembly consists of the barrel that is sealed at the lower end with a removable breech plug, which houses a removable firing pin (Figure 4-3). MORTAR RANGE: 500M X 100M X: FIELD TRAINING AREA 40000 Sq Ft: X STORAGE BUILDING, GENERAL PURPOSE, INSTALLATION: Area to store excess equipment X: ORGANIZATIONAL STORAGE BUILDING Arms room for Mortar equipment: X . If not, the cartridge is placed on its side, and the closing plug is removed using an M18 fuze wrench. If the primer is not dented, the round may be used again. The M252 is highly accurate up to ranges of 4500m to 5700m depending on the b. e. Dummy. M252 81mm Mortars The M252 81mm medium extended range mortar (see diagram below) is a crew-served, smooth bore, muzzle loaded, high angle of fire weapon system. The pile is covered with a double thickness of tarpaulin. The cartridge is painted olive drab with yellow markings. While the assistant gunner supports the barrel, the gunner slackens the leg-locking handwheel, releases the locating catch, and positions the plain leg. The assistant gunner attempts to maintain the traversing mechanism on a horizontal plane. The gunner is given a deflection and elevation change in a fire command causing the gunner to shift the mortar between 200 and 300 mils for deflection and between 100 and 200 for elevation. The cartridge can be fitted with the M524-series, M526-series, M567, or M532 fuzes. d. The M374A2, M374A1, and M374 HE cartridges are painted olive drab with yellow markings and are constructed from pearlitic malleable cast iron. General Dynamics Ordnance and Tactical Systems is the leading manufacturer of propellants for 60mm, 81mm and 120mm Mortar Systems. He exposes 4 inches (100 millimeters) of elevation shaft and folds the handle. The RSTA squadron only receives the 120mm mounted mortar, there is no augmentation dismounted maneuvers. The mortar is within two turns of center of traverse. Weights (pounds) System (including basic issue items) Barrel (with blast attenuator device) Mount M3A1 Baseplate Dropping may cause the propellant charges to ignite, causing bodily injuries. Placing the mortar in position at night does not relieve the gunner of the responsibility of checking for mask clearance and overhead interference. Bear in mind that these are my personal opinions, experiences, and . M224A1 60 MM LWCMS Mortar The 60mm mortar, M224A1 Lightweight Company Mortar System (LWCMS), is a smoothbore, muzzle loaded, high angle of fire weapon. Joint Tables of Allowance; PB - Professional Bulletins; STP - Soldier Training Publications; TC - Training Circulars; . This section discusses the. d. The gunner rough levels the cross-level bubble by making the bubble bounce from one side to the other. .50: BROWNING, M2 (HEAVY BARREL, FLEXIBLE) ON MOUNT, MACHINE GUN, TRIPOD MTD, CAL. Examples are: All mortar cartridges are painted to prevent rust and to identify their type. (1) The M935 fuze has two function settings: impact and delay. (1) Mask clearance and overhead clearance are sufficient. c. The assistant gunner moves into position to the front of the bipod on his right knee and grasps the bipod legs (palms up), lifting until they clear the ground enough to permit lateral movement. c. Authorized Cartridges. Home; Swifty. This round may be stored in a horizontal position. When set at SQ, the fuze functions on point impact or graze contact. Short cartridges can be expected when firing below charge 4. Army Publishing Directorate CANNON . It uses the M772 mechanical time fuze and weighs about 10.6 pounds. (3) Markings on rounds. The cartridge uses the M205 propelling charge and is assembled with the M567 or M524-series fuze. If the line of sight clears the mask, it is safe to fire. An 81 mm mortar is a medium-weight mortar. The adjustment ring has six raised ribs for use in conjunction with fuze setter, M25, and a setting indicator rib (marked SET) about half the height and width of the other six ribs. 9301 Chapek Road., Bldg.1458 The first table is a chart that shows range and elevation for firing particular mortar shells. It is set using the bladed end of the M18 fuze wrench. This round must be stored in a vertical position. The gunner places the announced deflection on the sight (without disturbing the lay of the weapon) and looks through the sightunit. f. Ammunition should be stored under cover. The explosive elements in primers and fuzes are sensitive to shock and high temperature. Each cartridge weighs about 10 pounds and is provided with the M223 propelling charge, consisting of four horseshoe-shaped increments fitted around the tail. Safety before firing is provided by a safety wire, which must be removed just before firing. VERY NICE condition! Proximity-fuzed short cartridges, which are duds, contain a complete explosive train and impact element. Complete cartridges are always handled with care. He lays for deflection, taking the proper sight picture. The cartridge uses the M218 propelling charge, which consists of four horseshoe-shaped increments fitted around the tail. Lock It should be destroyed in accordance with standard procedures. Red phosphorus cartridges (M252 only) are stored the same as HE cartridges. Illuminating is used for battlefield illumination and signaling. The fuze arms and functions normally when fired at any angle of elevation between 0800 and 1406 mils at charges 1 through 9. b. Cartridges assembled with the M524 (A1, A2, A3, or A4) fuze are for use by the US Marine Corps and US Navy only. The elevation change announced must be less than 90 mils and more than 35 mils. 4-10. He releases the securing strap, loosens the leg-locking handwheel, and lowers the plain leg until the locating catch engages in the recess. It is constructed from ductile cast iron and contains about 1.5 pounds of cyclonite (RDX)/trinitrotoluene (TNT) composition explosive. The air burst over average types of soil ranges from 1 to 6 meters, depending on the angle of approach. The gunner then kicks the barrel several times with his heel in an attempt to dislodge the round. All PD fuzes are superquick--detonate on impact. c. The elevating shaft is contained in the elevating leg; to the left of the elevating leg is the elevating handwheel. The term "indirect fire" means firing at an enemy without having a. Proximity fuzes withstand normal handling without danger of detonation or damage when in their original packing containers or when assembled to projectiles in their packing containers. MFCS Dismounted. The gunner checks the baseplate and ensures that--. The settings are obtained from the range tables and are applied using a wrench (number 9239539) or a 1 3/4-turn open-end wrench. (d) Firing is slowed if mask clearance must be checked before each firing but this can be eliminated if minimum mask clearance is determined. Their firing positions and principal duties are as follows: a. Tabulated data. HE Guided Mortar is in development. c. The M374A3 HE cartridge is constructed from pearlitic malleable cast iron and contains about 2.10 pounds of composition B explosive. The propellant train (except the training cartridge) consists of an ignition cartridge and propellant charges. Red phosphorus rounds can be fired from the M29/M29A1 at a reduced charge (maximum charge = charge 2). a. (2) The breech plug is screwed tightly to the barrel. The components of the mortar consist of a cannon, mount, and baseplate. The firing pin must be replaced and the bore swabbed. If the fuze does not function as set, it automatically functions at the next lower setting. Secure .mil websites use HTTPS He exposes 1 inch (25 millimeters) of cross-level shaft and folds the handle. A spring-loaded locating catch is behind the elevating gear housing, which locates the plain leg in its supporting position for level ground.