The components of the mortar consist of a cannon, mount, and baseplate. They function normally in light rain; however, heavy rain, sleet, or snow can cause an increase in the number of early bursts. It uses the M185 propelling charge that consists of eight increments fitted into the spaces between the fins and held by a propellant holder. The M821A2/821A1/889A1 consists of the following major components: M935 Point Detonating Fuze or M734/734A1 Multi-Option Fuze. e. Care, Handling, and Preservation. As soon as the sight data are announced, the gunner places it on the sight. 120mm IHE grenade DM91. The gunner stands to the left side of the mortar where he can manipulate the sight, elevating handwheel, and traversing handwheel. An ammunition lot number is assigned to each ammunition lot, which is marked on each cartridge and packing container. He moves the mortar until the vertical line of the sight is aligned approximately on the aiming post. Each round is stenciled with the ammunition lot number, type of round, type of filler, and caliber. The ignition cartridge (with primer) is fitted into the base of the fin shaft. With the clamps facing away from him, the assistant gunner traverses the buffer carrier to the traversing handwheel and folds the handle. Short cartridges can be expected when firing below charge 4. No tools are needed to set the fuze, and the setting can be changed several times without damaging the fuze. (1) The M772A1 fuze is a MTSQ.
(3) The securing strap is correctly located, securing the barrel clamps and buffers to the plain leg. . Figure 4-7. It weighs about 9.05 pounds. Several types of RP/WP ammunition are described herein. The cartridge is painted olive drab with yellow markings and weighs about 9.05 pounds. This section discusses the. The M734 multioption fuze is the only one used with the 81-mm mortar. CANNON . Powered by Hugo. While the assistant gunner supports the barrel, the gunner slackens the leg-locking handwheel, releases the locating catch, and positions the plain leg. The cartridge is painted light green with black markings and one narrow brown band. It engages the 1 3/4-inch flats on the setting ring or the fuze head. The 0-second boss is wider and differs in shape from the other body bosses; the safe setting position is indicated by the letter "S" on the fuze body. These are NDI items . The air burst over average types of soil ranges from 1 to 6 meters, depending on the angle of approach. They are assembled with either an M524-series, M526-series, or M567 fuze. 0.50, M8 (REPRINTED W/BASIC INCL C1-2) (S&I BY PROP SEE DETAILS, FOOTNOTES), FIRING TABLES FOR MACHINE GUN, CALIBER .50: BROWNING, M2 (HEAVY BARREL, TURRET TYPE) ON MOUNT, MACHINE GUN, TRAILER MOUNTED: MULTIPLE CALIBER .50 MACHINE GUN, M55 FIRING CARTRIDGE, CALIBER .50: API, M8 (S&I BY PROP SEE DETAILS, FOOTNOTES), FIRING TABLES FOR MACHINE GUN, CALIBER .50: FICED, M85 TANK, COMBAT, FULL TRACKED: 105MM GUN, M60 SERIES FIRING CARTRIDGE, CALIBER .50: API, M8 CARTRIDGE, CALIBER .50: API-T M20 CARTRIDGE, CALIBER .50: BALL, M33 CARTRIDGE, CALIBER .50: TRACER, M17 (S&I BY PROP SEE DETAILS, FOOTNOTES), MACHINE GUN, CAL. This document (FT 81 B3, abridged) consists of two pages, each with a separate table. 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. high-explosive bomb at a range of about three miles. To prepare for firing, the slot is aligned in the striker with SQ or delay using the M18 fuze wrench. The round is still safe to handle and transport if the safety wire is reinserted. The squad leader picks up the sight case and the two aiming posts, and moves to the exact position where the mortar is to be mounted. That is generally how I use mortars. Fuzes are not disassembled. c. The first ammunition bearer checks the barrel and ensures that--. The gunner checks the baseplate and ensures that--. After the rounds have been removed, they should always be handled with two hands to prevent accidental dropping. When cartridges have been prepared for firing, but are not used, all powder increments and safety wires are replaced. c. The assistant gunner disengages the barrel clamps and moves the bipod from the immediate area of the mortar position. There must not be a visible gap between the fuze and cartridge body. The 81mm mortar rounds use Red Phosphorus as the smoke generating agent. The mortar is mounted and the sight is installed. The squad leader indicates the direction of fire when mounting. a. Identification. Designed by Thingsym. He maintains the ammunition for firing and provides local security for the mortar position. The firing pin must be replaced and the bore swabbed. When targets are beyond such irregularities, a clearance of at least 30 meters should be allowed to ensure maximum effect over the target area. The fuzes may be used for day or night operations. It can be set from 3 to 55 seconds at half-second intervals. M252A1 81mm Mortar: Maximum Range (meters): 5,935; Ammunition: War reserve HE (M821A3), red phosphorus smoke (M819), visible light illumination (M853A1), infrared illumination (M816), war reserve and training HE (M889A4), and FRP . He levels all bubbles. The 81-mm mortar, M252, is a smooth-bore, muzzle-loaded, high-angle-of-fire weapon. FIRING TABLE FOR CANNON, 155MM HOWITZER, M185 ON HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A1; HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A1B; HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A2; HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A3; AND HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A3B; AND CANNON, 155MM HOWITZER, M284 ON HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A5 AND HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A6 AND CANNON, 155MM HOWITZER, M199 ON HOWITZER, MEDIUM, TOWED, 155MM, M198 FIRING PROJECTILE, GUIDED, M712 (COPPERHEAD) WITH SHAPED TRAJECTORIES (S&I BY PROP SEE DETAILS, FOOTNOTES), PROVISIONAL AIMING DATA FOR CANNON, 155MM, HOWITZER, M185 ON HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, 109A1 HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, 109A1B HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A2 AND HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A3 HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A3B AND HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A4 AND CANNON, 155MM HOWITZER, M284 ON HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A5 AND HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A6 AND CANNON, 155MM HOWITZER, M199 ON HOWITZER, MEDIUM, TOWED, 155MM, M198 AND CANNON, 155MM HOWITZER, M776 ON HOWITZER, MEDIUM, TOWED, 155MM, M777A1 FIRING PROJECTILE, BASE-BURN, M864 AND M864A1 (S&I BY PROP SEE DETAILS, FOOTNOTES), PRELIMINARY AIMING DATA FOR CANNON, 155MM HOWITZER, M284 ON HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A6 AND CANNON, 155MM HOWITZER, M776 ON HOWITZER, MEDIUM, TOWED, 155MM, M777A2 FIRING PROJECTILE, HE, XM982 (S&I BY PROP SEE DETAILS, FOOTNOTES), PROVISIONAL AIMING DATA FOR CANNON, 155MM HOWITZER, M284 ON HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A6 AND CANNON, 155MM HOWITZER, M776 ON HOWITZER, MEDIUM, TOWED, 155MM, M777A2 FIRING PROJECTILE, HE, XM982 (S&I BY PROP SEE DETAILS, FOOTNOTES), PROVISIONAL AIMING DATA FOR CANNON, 155MM HOWITZER, M284 ON HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A6 AND CANNON, 155MM HOWITZER, M776 ON HOWITZER, MEDIUM, TOWED, 155MM, M777A2 FIRING PROJECTILE, HE, M982 (S&I BY PROP SEE DETAILS, FOOTNOTES), CANNON, 165-MM GUN, M135 ON COMBAT ENGINEER VEHICLE, FULL TRACKED, M728; FIRING CARTRIDGE, 165-MM, HEP, M123A1 AND 165-MM, TP-T, XM623 (S&I BY PROP SEE DETAILS, FOOTNOTES), CANNON, 175-MM GUN, M113 AND M113A1 ON GUN, FIELD ARTILLERY, SELF-PROPELLED: 175-MM, M107; FIRING PROJECTILE, HE, M437A2 AND M437A1 (S&I BY PROP SEE DETAILS, FOOTNOTES), RAPID FIRE TABLES FOR CALCULATION OF THE EXECUTIVE OFFICERS (XOS) MINIMUM QUADRANT ELEVATION WITH CANNON, 105MM HOWITZER, M20A1 ON HOWITZER, LIGHT, TOWED, 105MM, M119A1; HOWITZER, LIGHT, TOWED, 105MM, M119A2; HOWITZER, LIGHT, TOWED, 105MM, M119A3 FIRING WITH PROPELLING CHARGES, M67 AND M200 (S&I BY PROP SEE DETAILS, FOOTNOTES), RAPID FIRE TABLES FOR CALCULATION OF THE EXECUTIVE OFFICER S (XO S) MINIMUM QUADRANT ELEVATION WITH CANNON, 155MM HOWITZER, M284 ON HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A5/A6 AND CANNON, 155MM HOWITZER, M199 ON HOWITZER, MEDIUM, TOWED, 155MM, M198 AND CANNON, 155MM HOWITZER, M776 ON HOWITZER, MEDIUM, TOWED, 155MM, M777A1/A2 FIRING WITH PROPELLING CHARGES, M231, M232, AND M232A1 (S&I BY PROP SEE DETAILS, FOOTNOTES), RAPID FIRE TABLES FOR CALCULATION OF THE EXECUTIVE OFFICERS (XOS) MINIMUM QUADRANT ELEVATION WITH CANNON, 155MM HOWITZER, M284 ON HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A5; HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A6; AND HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A7, AND CANNON, 155MM HOWITZER, M776 ON HOWITZER, MEDIUM, TOWED, 155MM, M777A1 AND HOWITZER, MEDIUM, TOWED, 155MM, M777A2 FIRING WITH PROPELLING CHARGES, M231, M232, AND M232A1 (S&I BY PROPONENT, SEE DETAILS, FOOTNOTES), ADDENDUM TO FTR LANCE-B-1 FOR WARHEAD SECTION, GUIDED MISSILE, HE: M251 (U) (S&I BY PROP SEE DETAILS, FOOTNOTES), Search Army publications and forms by Number, Title, or Record Detail. (3) The M84A1 fuze is a single-purpose, tungsten-ring, mechanical-time fuze used with the 81-mm M301A3 illumination cartridge. Section I. e. The pull wire and safety wire are removed from the fuze just before firing. With the mortar mounted and the sight installed, the gunner lays the sight on the two aiming posts (placed out 50 and 100 meters from the mortar) on a referred deflection of 2800 mils and an elevation of 1100 mils. The American M1 81mm Mortar, like the upcoming M2 60mm Mortar, was based on a French design by Edgar William Brandt (1880-1960). In any case, the gunner must ensure that the cartridge does not strike an obstacle. Agreed that mortars should generally be used close to the frontline. a. Cartridges are shipped with a complete propelling charge, an ignition cartridge, and primer. The fuze should already be fitted to the cartridge. REFER DEFLECTION TWO EIGHT SEVEN FIVE (2875), REALIGN AIMING POSTS. An 81 mm mortar is a medium-weight mortar. The 0-second boss is wider and differs in shape from the other body bosses; the safe setting position is indicated by the letter "S" on the fuze body. The components of the mortar consist of a canon, sight, mount, and baseplate. The tabulated data of the 81-mm mortar, M252, are shown in Table 4-1. Disposal Precautions. e. The squad leader picks up the aiming posts and sight. The M853 cartridge (M252 only) has a cylindrical body that contains an illuminating candle and parachute assembly. If not, the cartridge is placed on its side, and the closing plug is removed using an M18 fuze wrench. a. The M821 HE cartridge (M252 only) is a British-made cartridge fitted with the US M734 multioption fuze. Proximity-fuzed short cartridges, which are duds, contain a complete explosive train and impact element. If not, he may still fire at the desired range by selecting a charge zone having a higher elevation. On its right side, the clamp is recessed to receive the ball end of the locking rod. The elevation change announced must be less than 90 mils and more than 35 mils. 4-11. The cannon has a crew-removable breech plug and firing pin. Army Publishing Directorate
The leg-locking handwheel must then be tightened by hand, ensuring the teeth on either side are correctly meshed. (6) The primer cartridge is checked for damage or dampness. He tightens the leg-locking handwheel (ensuring the teeth are correctly meshed) and fastens the securing strap over the arm and around the buffers. Tabulated data. The terms cannon and barrel are used interchangeably in this chapter. M64A1 Sightunit. The ignition cartridge strikes the firing pin and detonates, which causes a flash that passes through the radial holes in the shaft. 9301 Chapek Road., Bldg.1458
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. Ammunition is typed according to use (Table 4-2). Normally, it can be moved by hand, although this may be difficult to do if the mortar is moved through a large arc. Any target that requires that elevation, or a lower one, cannot be engaged from that position. The fuze arms and functions normally when fired at any angle of elevation between 0800 and 1406 mils at charges 1 through 9. The following are authorized (Standard B) cartridges for the 81-mm mortar, M252: Each cartridge has fins around the tail to stabilize it in flight and to cause it to strike fuze-end first. With the mortar mounted and the sight installed, the gunner lays the sight on the two aiming posts (placed out 50 and 100 meters from the mortar) on a referred deflection of 2800 mils and an elevation of 1100 mils. I have included my order history, detailed photos, as well as my personal opinion on International Military Antiques, IMA -USA www.ima-usa.com 81mm Display Mortar that they have for sale. c. The elevating shaft is contained in the elevating leg; to the left of the elevating leg is the elevating handwheel. See Chapter 3, paragraph 3-14 for a detailed discussion of malfunctions. a. SQUAD AND SECTION ORGANIZATION AND DUTIES, Each member of the infantry mortar squad has principle duties and responsibilities. (2) Color code. The following safety checks must be enforced before firing the mortar. Cartridges assembled with the M532 fuze must be fired above charge 0. It has two types: type 1 resembles the M734 fuze, and type 2 resembles the M935 fuze. Each squad member should be able to perform all the following premount checks: a. The gunner removes the sight and places it in the case with 3200 deflection and 0800 elevation indexed. The powder increments, mainly, should not be exposed to direct sunlight. The fuze contains a delayed arming feature that ensures the fuze remains unarmed and detonator safe for a minimum of 1.25 seconds of flight. The enemy will use them. c. Mechanical Time. The M751 is fitted with a smoke charge that operates on impact. If the mortar section is to operate quickly and effectively in accomplishing its mission, mortar squad members must be proficient in individually assigned duties. When a large number of cartridges are needed for a mission, they may be removed from the containers and prepared. Several types of HE ammunition are used in the 81-mm mortar, M252. The cartridge uses the M205 propelling charge and is assembled with the M567 or M524-series fuze. 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 . The M821/M889 are 81mm HE Mortar Cartridges. 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. 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. b. The M252 81mm mortar is a smooth-bore, muzzle-loaded, high-angle-of-fire weapon. Table 4-3. He stands to the rear of the baseplate and supports the barrel until the bipod is fitted. The first table is a chart that shows range and elevation for firing particular mortar shells. on Amazon.com. In addition to supervising the emplacement, laying, and firing of the mortar, he supervises all other squad activities. Training practice--M879, M880, M68, and sabot. The increments are individually wrapped with waterproof bags that are not removed. The gunner places the outer edge of the baseplate against the baseplate stake so that the left edge of the cutaway portion of the baseplate is aligned with the right edge of the stake (Figure 4-7). During training, the gunner may use the driving stake from the aiming post case. Weights (pounds) System (including basic issue items) Barrel (with blast attenuator device) Mount M3A1 Baseplate The assistant gunner checks the bipod and ensures that--. It has four function settings: PRX (proximity) causes the cartridge to explode between 3 and 13 feet above the ground; NSB (near-surface burst) causes the cartridge to explode up to 3 feet above the ground; IM (impact) causes the cartridge to explode on contact; and DLY (delay) incorporates a 0.05-second delay in the fuze train before exploding the cartridge. The propelling charge is contained in four horseshoe-shaped, felt-fiber containers or nine wax-tested, cotton cloth, bag increments. The first ammunition bearer holds the barrel until the assistant gunner has removed the mount. The mortar also offered the promised increase in range as well, allowing fire teams to engage the enemy at distance. The M1 became the standard American . It is especially useful if the baseplate sinks deep into the ground during prolonged firing. c. The assistant gunner stands to the right of the mortar, facing the barrel and ready to load. This cartridge is ballistically matched to the M374A2, M374A1, and M375 HE cartridges, and weighs about 9.12 pounds. (4) The M567 fuze is an impact fuze that has a SQ/IMP or D function. He exposes 1 inch (25 millimeters) of cross-level shaft and folds the handle. 81mm smoothbore mortar Barrel length 1.28 m Muzzle velocity 225 m/s Elevation +45 to +85 Traverse 18 Fire control Sights C2 indirect fire sight with illumination Firepower Rate of fire 20 rpm maximum 15 rpm normal 1 to 12 rpm sustained Range 5.650 m maximum 100 m minimum Media 81mm L16A2 After the barrel cools, the gunner removes the sight and firing pin. A proximity fuze is an electronic device that detonates a projectile by means of radio waves sent out from a small radio set in the nose of the projectile. The second page includes a chart with range and deflection (presumably for the same kind of shells), as well as notes which give additional instructions. Ammunition Lot Number. They are fuzed with the M524-series, M256-series, or M532. The types of fuzes described in this paragraph are point detonating, proximity, mechanical time, multioption, and dummy. (b) In selecting the exact mortar position, the leader looks quickly for mask clearance and overhead interference. Cartridges assembled with the M524 (A1, A2, A3, or A4) fuze are for use by the US Marine Corps and US Navy only. ), FIRING TABLES FOR CANNON, 155MM HOWITZER, M185 ON HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A1 HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A1B HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A2 HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A3 HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A3B AND HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A4 AND CANNON, 155MM HOWITZER, M284 ON HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A5 AND HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A6 AND CANNON, 155MM HOWITZER, M199 ON HOWITZER, MEDIUM, TOWED, 155MM, M198 AND CANNON, 155MM HOWITZER, M776 ON HOWITZER, MEDIUM, TOWED, 155MM, M777A1 FIRING PROJECTILE, HE, M483A1 (S&I BY PROP SEE DETAILS, FOOTNOTES), FIRING TABLES FOR, CANNON, 155MM, HOWITZER, M185 ON HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, 109A1 HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, 109A1B HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A2 HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A3 HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A3B AND HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, 109A4 AND CANNON, 155MM, HOWITZER, M284 ON HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, 109A5 AND HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, 109A6 AND CANNON, 155MM, HOWITZER, M199 ON HOWITZER, MEDIUM, TOWED, 155MM, M198 AND CANNON, 155MM HOWITZER, M776 ON HOWITZER, MEDIUM, TOWED, 155MM, M777A1 FIRING PROJECTILE, HERA, M549 PROJECTILE, HERA, M549A1 (S&I BY PROP SEE DETAILS, FOOTNOTES), FIRING TABLES FOR CANNON, 155MM HOWITZER, M185 ON HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A1; HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A1B; HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A2; HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A3; HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A3B; HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A4 AND CANNON, 155MM HOWITZER, M284 ON HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A5, M109A6 AND M109A7 AND CANNON, 155MM HOWITZER, M284A2 CHROME ON HOWITZER, MEDIUM, SELF-PROPELLED, 155MM, M109A6 AND M109A7 AND CANNON, 155MM HOWITZER, M199 ON HOWITZER, MEDIUM, TOWED, 155MM, M198 AND CANNON, 155MM HOWITZER, M776 ON HOWITZER, MEDIUM, TOWED, 155MM, M777, M777A1 AND M777A2 AND CANNON, 155MM HOWITZER, M776 CHROME ON HOWITZER, MEDIUM, TOWED, 155MM, M777A2 FIRING PROJECTILE, HERA, M549 AND PROJECTILE, HERA, M549A1 (S&I BY PROPONENT, SEE DEAILS, FOOTNOTES. When the approximate alignment is completed, the gunner signals the assistant gunner to lower the bipod by pushing down on the mortar. d. The M374A2, M374A1, and M374 HE cartridges are painted olive drab with yellow markings and are constructed from pearlitic malleable cast iron. 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. The components of the mortar consist of a cannon, mount, and baseplate. If, upon removal of the safety wire, a buzzing sound in the fuze is heard, the round should not be used. XM1210. The squad leader points to the exact spot where the mortar is to be mounted. a. The assistant gunner attempts to maintain the traversing mechanism on a horizontal plane. The squad leader notifies the FDC of the minimum mask clearance elevation. At extreme temperatures (below -40 degrees Fahrenheit and above 125 degrees Fahrenheit), it is not unusual to experience an increase in malfunctions proportionate to the severity of conditions. With standard mortar, the maximum effective range is close to 4,000 metres; with a long-range system, this increases to nearly 4,500 metres. (2) The M84 fuze is a single-purpose, powder-train, mechanical-time fuze used with the 81-mm M301A1 and M301A2 illuminating cartridges. Prev - Mk6 Mortar range table for charge 0 Next - Mk6 Mortar range table for charge 2 . 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. This section implements STANAG 2321 and QSTAG 900 (Edition 1). He knocks down the near aiming post and proceeds to the far aiming post. a. Long Range PGK. (7) When opening an ammunition box, the ammunition bearer ensures the box is horizontal to the ground, not nose- or fin-end up. 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. Additional information is included on an ammunition data card inside each container. The same procedure for aligning the far aiming post is used to align the near aiming post. How the RCGM works: Target coordinates are programed into the RCGM using a portable GPS setter. These fuzes use a clockwork mechanism to delay functioning for a specific time. b. The M252 medium mortar offers a compromise between the light and heavy mortars. The squad leader stands behind the mortar where he can command and control his squad. d. The squad leader supervises the squad drill and is responsible for supervising the laying out of the equipment as shown in Figure 4-6. He has the duty of preparing the ammunition and passing it to the assistant gunner. SMALL DEFLECTION AND ELEVATION CHANGES. During firing, the breech plug on the barrel is sealed and locked to the rotatable socket in the baseplate. Theme by TechDoc. Each cartridge weighs about 10 pounds and is provided with the M223 propelling charge, consisting of four horseshoe-shaped increments fitted around the tail. (703) 614-3727, Office of the Chief Information Officer
The safety/packing clip should be removed when the cartridge is unpacked. (2) The ribs and braces have no breaks, cracks, or dents. At this command, the squad proceeds as follows: a. Overhead interference can be branches of trees or roofs of buildings. More uniform firing is obtained if ammunition is kept at the same temperature. OPERATOR`S MANUAL FOR MORTAR, 81-MM, M252 (NSN 1015-01-164-6651) (EIC 4SK){TM . When a misfire occurs, any member of the squad immediately announces, "Misfire." (5) Do not leave unused increments unburned in combat operational areas. The pile is covered with a double thickness of tarpaulin. If it is necessary to leave the ammunition uncovered, it should be raised on dunnage at least 6 inches above the ground. Table 4-2. The leg-locking handwheel must then be tightened, ensuring the teeth are correctly meshed. (4) The bipod locking latch is locked, securing the barrel clamps. (5) With the exception of a few unused increments (within the same ammunition lot number) as replacements for defective increments, excess powder should be removed from the mortar position. 4-4. The M29 would become the standard American mortar in the upcoming Vietnam War. If the situation allows for a longer waiting period, the dud can be considered safe for handling after 40 hours. An official website of the United States government. 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. When fired, the cartridge carries the ignition cartridge with it, leaving the mortar ready for the next cartridge. (4) The leg-locking handwheel is hand tight. b. (3) From this train, extend a starting train that will burn against the wind of single increments laid end to end. The cartridge can be fitted with the M524-series, M526-series, M567, or M532 fuzes. The fuze consists of a brass head, body assembly, and expelling charge. ) or https:// means youve safely connected to the .gov website. An internal clock mechanism provides nine seconds of safe air travel (610 to 2,340 meters along trajectory for charge 0 through 9, respectively). HE ammunition is used against personnel and materiel. Burst Height. LARGE DEFLECTION AND ELEVATION CHANGES. The M252 system . d. The ammunition is protected from mud, sand, dirt, and water. The assistant gunner cleans the bore and swabs it dry. He opens the cross-level handwheel, traversing handwheel, and barrel clamp. 0.50, BROWNING, M2; FIRING CARTRIDGE, ARMOR-PIERCING-INCENDIARY, CAL. The ammunition that can be fired by the 81-mm mortar, M252, is identified and described herein. The upper clamp is fitted with a locking arrangement that consists of a curved handle and a spring-loaded locking rod, which is ball-shaped at its lower end. He performs other duties as the squad leader directs. The cartridge uses the M218 propelling charge, which consists of four horseshoe-shaped increments fitted around the tail. Lock
(4) Extra increments are removed if the cartridge is to be fired with less than full charge. FT 81-AI-3 Firing Tables Mortar, 81mm: M28A1 and M29 Mortar 81mm Self propelled M125A1 and M125 Carrier, 81mm Mortar Tracked XM755 [US Army.]