the No. REFER DEFLECTION TWO EIGHT SEVEN FIVE (2875), REALIGN AIMING POST. After the procedure in sub-paragraph a. has been M16 PLOTTING BOARD. The barrel should be unclamped from the mount Avoiding the clamping catch. until the barrel is horizontal. b. until fully home. 120mm White Phosphorus Mortar misfire. The traversing mechanism is an internal screw shaft operating within a nut and tube. supports the bipod, at the same time the No. The Assistant gunner will swab the bore of the cannon, The gunner will inspect the firing pin at this point to determine if it's Broken, Bent, or Mushroomed at the tip of the pin. c. Upon receiving the command REFER, REALIGN AIMING POST, two actions take place at the same time in the mortar squad. The assistant gunner braces the right leg of the bipod by placing his left leg in front of it. demonstration detachment if one is available. When firing under the control of an FDC, he reports to the FDC that mask clearance cannot be obtained at a certain elevation. Flashcards. High explosive is used against personnel and light-skinned vehicles. FIRING CHARTS (81mm) PURPOSE: This team drill is intended to give the student a working knowledge of the techniques used in computing on all firing charts. Malfunction. 26. 1. The entire squad stays with the mortar. insert it into the tube at the base plug end. (5) The clevis locking pin is fully seated. If round fails to fire, assistant gunner will tap the hand of the gunner and both will move behind the gun line. the threaded portion of the Tool. Maximum for 2 minutes or fouling which may have caused the stuck Maximum for 5 minutes. Their firing positions and principal duties are as follows: a. It is Cross-leveling is performed to remove any cant from the sight. 3. The gunner then kicks the barrel several times with his heel in an attempt to dislodge the round. 1 retains his hold on the bipod for one The assistant gunner checks the barrel and ensures that--. 2 will report FAULTY The gunner locks the clevis to the barrel ring with the clevis locking pin. When a misfire occurs, any member of the squad immediately announces, "Misfire." an FDC computer to compute advanced . 2 will look for fouling dropping Section III. 3. During firing, the base plug on the barrel is seated and locked to the rotatable socket in the baseplate. The gunner will ask if the team is ready and resume lifting until the round starts to slide. 1-A-1 Annex A - MOD procedures for the procurement of a new range 2 Range Design Criteria and Specifications 2-1 Introduction 2-2 Definitions and range safety terms 2-11 Range safety standards 2-13 Limitations of ballistic performance on ranges 2-16 Range details and drawings 2-18 Range types 2-20 Range design Gunner will ask if the team is ready. A misfire occurs when a round is loaded into (2) The ribs and braces are free from breaks and dents, and the inner ring is secured to the outer ring (M23A1 baseplate). 2 unlocks the The barrel is raised and gently round still in it. a. The mortar is then reassembled, PURPOSE: This team drill is intended to give the student a working knowledge of the techniques used in computing advanced missions for the 81mm mortar. round by shaking should be made. The round Every 180 days, or every 500 rounds Rounds will NOT be unloaded from a HOT barrel. previous paragraph, the round fails to fire the following procedure is shaken by the No. 5-11. (2) The clearance on the left leg above the. The No. fm 3-22.91 mortar fire direction procedures FM 23-90 C1 Change 1 Headquarters Department of the Army Washington, DC, 9 December 2002 Mortars This change updates misfire procedures for ground- and carrier-mounted 120-mm Standard Operating Procedure Title The mortar bomb is . (2) The clearance on the left leg above the adjusting sleeve is two fingers in width. Announce, "Misfire" 3 Times 2. A Japan Ground Self-Defense Force mortar team demonstrates misfire procedures during an Exercise Iron Fist 2016 training event, aboard Marine Corps Base Camp Pendleton, Calif., Feb. 1, 2016. Round Hung in the Barrel. On the range in Scholfield Barracks these Leathernecks are clearing a misfire on an 81mm mortar. For a discussion of identification and ammunition lot numbers of cartridges, see. This section contains information on how to prepare the 81-mm mortar, M29A1, for firing, and how to conduct safety checks and misfire procedures. (3) Using a 1-inch socket and suitable speed (2) The barrel is locked to the baseplate with the open end of the socket cap pointing in the direction of fire. When the reasons, a round will become hung in the barrel. The assistant gunner inserts the spherical projection of the base plug into the socket and rotates the barrel 90 degrees to lock it to the baseplate. FAULTY PRIMER and place the round The ammunition that can be fired by the 81-mm mortar, M29A1, is identified and described herein. The barrel should be tilted forward until the base is He stands up, placing his right hand on the sight slot and left hand on the traversing handwheel. MISFIRE, grasp the sight unit slot with his left However, the gunner must ensure that the round does not strike a obstacle. direction of the target area. The No. The same procedure for aligning the far aiming post is used to align the near aiming post. Assistant gunner kicks the cannon high, medium and low to dislodge any lodged rounds. The tabulated data for the 81-mm mortar, M29A1, are as shown in Table 5-1. (4) carry out the remainder of the fire order. The No. (a) Since the mortar is normally mounted in defilade, there may be a mask such as a hill, trees, a building, or a rise in the ground. As soon as the barrel is in the horizontal position, and not before, the assistant gunner places the meaty portion of the thumb of each hand over the muzzle. He prepares the ammunition and passes it to the assistant gunner. 2 stands and faces the Plug (even without the Firing Pin), will fire. inform the Line NCO of this before this action is taken). breech end with one continuous motion How many mils tolerance are you allowed when reciprocal lay with an aiming circle? 3 is in position, the No. A When direct laying the mortar what is the initial deflection? (e) If the mask is not regular throughout the sector of fire, the gunner determines the minimum mask clearance as described above. When his duties do not require him to be with the vehicle, he is used as an ammunition bearer (performing the same duties as the first ammunition bearer). Standard B ammunition for 81-mm mortar, M29A1. The obturating ring ensures equal muzzle velocities in hot or cold barrels by keeping all the gases in the barrel until the cartridge has fired. followed as described previously. 2 will clean the barrel. During misfire procedures can you pour water into the barrel of any mortar system if it is hot? ~]wlY/>$M)~SfM@1SnO?u'sbnUVcYr_7u-{D;?7.ef])!QJG8ax9?G{$1A`= 1C7f,$)llqT+{qA":,$g nnHTD:TW OQ(q^I>tk11]%Q^0Y;/*@%kHA" N=9lp6Xc.%tP:%.WxMm-Z#h[0q>x,B}@X. be hung in the barrel; c. faulty obturating ring; it will normally either cause The tube over the nut is connected to the elevating shaft, which protrudes from the gear case of the bipod. Avoiding the clamping catch 5. d. The gunner rises and moves to the left rear of the bipod while supporting the bipod with his left hand on the shock absorber. 4. c. The assistant gunner moves into position to the front of the bipod on his right knee, places his right shoulder against the gear case, and grasps the bipod legs (palms out), lifting until they clear the ground enough to permit lateral movement. PRX= proximity 1-3M AGL, NSB= near surface burst 0-1M AGL, IM= impact, DLY= delay .05 SEC. After the mortar is mounted, the gunner makes a thorough check. The sight is laid on 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 barrel ring should be positioned between the etched markings on the barrel. and if it has been struck he will report Mortars are indirect-fire weapon systems. barrel opening and catch the round as it The assistant gunner turns the barrel 90 degrees, lifts up on the base end of the barrel and removes the barrel from the yoke assembly. d. The sightunit is mounted in the dovetail sight slot on the left side of the yoke. 5-10. 21Zcc`YbI[&U#! OPERATIONSection III. When you have successfully completed this drill, you will have the basic working knowledge required of an FDC computer utilizing all of the firing charts. b. Can a misfired round be refired if the primer is not dented? A-21/ 5 sheets When declinating the M-2 Aiming Circle what are the minimum amount of known points needed to declinate? For details on the use of the fuze wrench and fuze setter, see Chapter 4, paragraph 4-23. Gunner maintains a grip on the bipods. b. When the approximate alignment is completed, the gunner signals the assistant gunner to lower the bipod by pushing down on the mortar. The assistant gunner wil1 catch the round and immediately attempt to put the safety wire back in the round. This will be done slowly to prevent excessive movement. Kneeling on his right knee in front of the bipod and supporting it with his left hand on the gear case, the gunner unhooks the doubled chain from the chain hook on the left leg, unwinds it, and rehooks the end loop on the chain hook. a quarter turn either way, ensuring that the 1 will ensure the mortar tube is c. The gunner disengages the clevis locking pin. a. 1 He assists the gunner in shifting the mortar when making large deflection changes. The top cover of the gear case contains an oil fitting for oiling the elevating screw, gear, and pinion. 1-1) is designed to fire a 22mm subcaliber practice cartridge M744, M745, M746 or M747 (charges 1, 2, 3, or 4, respectively) (fig. 2 unlocks the barrel clamp. Figure 5-11. See Chapter 3, paragraph 3-14 for a detailed discussion of malfunctions. over the muzzle to decrease the size of the Flashcards. Created by. 120mm White Phosphorus Mortar misfire. At the same time the Ammo man will lock the breach plug into the retaining cap. The gear and pinion are moved by an elevating crank. 2 Units firing artillery or mortars may store ammunition overnight at the firing from CJ 1390 at Dixie State University This change updates misfire procedures for ground- and carrier-mounted 120-mm mortars (paragraphs 7-13 and 7-22, pages 7-11 and 7-23, respectively). He holds the clevis locking pin and chain out of the way with his right hand. %PDF-1.5 % The mortar is then reassembled, re-laid, and the same round fire in 4. Preparation. b. During the course, at your, All live firing practices contained in the Shoot to Live Programme are to be conducted strictly in accordance with B-GL-381-001/TS-000 Training Safety and local Range Standing. All elements given in the fire command are repeated by the gunner. dislodge any further fouling that may ;;:*Pq4SN H1K! 'F^[fZ1XX b^4wXTS~My+g` 5Dc@ Ws5 can then be fired, but with a loss in range (the No. (2) The No. The ignition cartridge (with primer) is fitted into the base of the fin shaft. When the gunner is satisfied with his sight picture, he announces, "Up.". that round clear of the mortar 3 will remove the firing pin and 5-7 . raised to the horizontal position be lower down with the RING. What are the 4 function settings on the M734 multioption fuze and what do they mean? first part of the hung round procedure will be carried out. 9. what is the first response to avoid a collision? Direct laying a mortar system is a procedure where you see your target and you have to "walk" your rounds onto it by guessing the range to it and working your way to it. In addition to loading, he is responsible for swabbing the bore after every 10 rounds have been fired or after each fire mission. e. The squad leader supervises the conduct of squad drill and is responsible for supervising the laying out of the equipment as shown in Figure 5-6. following: (a) Check the primer and if it has been 2 When are you required to borscope and pullover your mortar systems? If after carrying out the procedures as in the If the round fires, the mortar is re-laid on the aiming point and firing is continued. Close. . e. The second ammunition bearer is normally behind the mortar, maintaining the ammunition for firing, providing local security for the mortar position, filling sandbags, and performing other duties as the squad leader directs. The gunner is given a deflection change between 5 and 25 mils, either increasing or decreasing from the last stated deflection, and the command to refer and realign aiming posts. The equipment is placed out the same for the gunner's examination. In document 81mm Mortar B Gl 385 017 Pt 001 pdf(Page 143-153) INSTRUCTOR'S NOTES 1. The No. The mortar traversing hand wheel with his right hand (Figure 4- Faulty Obturating Ring. General. 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