JAG Ire? 13% 9?73?? TRAINING CIRCULAR HEADQUARTERS, DEPARTMENT OF THE ARMY No. 23?3 WASHINGTON 25, D.C., 2 November 1960 GRENADE LAUNCHERS, XM79 AND. T148E2 Paragraphs Page CHAPTER 1. DESCRIPTION AND MECHANICAL TRAIN- ING Section I. Introduction . 1, 2 2 II. Mechanical training . . . . 3?6 2 Ammunition . . . . '7 6 IV. Capabilities and 8, 9 8 V. Safety precautions and technique of ?re 10, 1 1 8 CHAPTER 2. TACTICAL EMPLOYMENT Section I. Introduction .. . . 12, 13 10 II. 14419 10 Defense . . '20?24 12 TA G0 2710B?Nov. 5704 81 ??60 TC 23?3 CHAPTER 1 DESCRIPTION AND MECHANICAL TRAINING Section I. INTRODUCTION 1. Purpose and scope. This circular provides information to come manders, sta? of?cers, and other concerned individuals, on the XM7 9 and T148E2 grenade launchers and their associated ammunition. It covers mechanical training, technique of ?re, and tactical employment of the launchers in su?icient detail to be used by of?cers and to train quali?ed grenadiers and to employ the weapon in tactical op erations . 2. General. a. The XM79 and the T148132 grenade launchers, employing HE ammunition, permit the concentration of lethal ?re in a selected area at ranges varying from the maximum distance the average soldier can throw a hand grenade (about 40 meters (43?44 yards)) to the minimum mortar support range (about 400 meters (435 yards)). The launchers may be employed against area or point targets. 6. Since the launchers are organic to the ri?e squad?s ?re teams, they provide small infantry units with their own ?re support with minimum safety?distance restrictions and without the time delay that is usually incurred in obtaining comparable support from other sources. Section II. MECHANICAL TRAINING 3. Description. a. The XM79 grenade launcher is shown in ?gure 1. It is a single?shot, break?open, percussion ?red, shoulder weapon that ?res 40-mm projectiles. b. The T148E2 grenade launcher is shown in ?gure 2. It is a 3? round, magazine fed, semiautOmatic, shoulder weapon that ?res 40? mm projectiles. TAGO 271013 TC 23?3 Figure I. The XM 1V9 grenade launcher. emu? {3m wane Figure 2. The T148132 grenade launcher. TAGO TC 23?3 6. The 4 following are comparative descriptive data on the XM79 and the T148E2 launchers: X11179 7'1485'3 Weight loadedl 6.71 lb 8.41 lb. Unloaded 6.16 lb - 6.63 lb. Length (overall) 28.62 in - 29.5 in. Barrel: Weight (barrel group) 1.51 lb 1.3 lb. Length 14.71 in 12.00 in. Ri?ing: Length 14.00 in 12.00 in. Number of grooves_-r__ - 6 6. Depth of grooves 0.01 in 0.01 in. Twist, uniform, right 48. 00 in .. 48.00 in. hand, one turn in. Action Break-open, shot? Semiautomatic. gun type. Magazine operation None a- Negator spring. Number of rounds 1 3. Sights: Front (adjustable in azi? Blade Blade. muth). Rear - Folding leaf, Folding leaf, mounted on mounted on barrel. barrel. Muzzle velocity -1 250 f.p.s _1 250 f.p.s. Maximum range- Minimum 400 m. (435 50 m. (54?55 400 m. (435 range n- 50 m. (54?55 4. Assembly and disassembly. See TM 9~1010?205?12, ?Oper- ational and Organizational Maintenance, Grenade Launcher, (when published). 5. Loading. a. X21479. (2) To load the XM79 1), ?rst press the barrel locking latch to the right. This unlocks the barrel from the receiver and moves the actuator rearward, pushing the safety mecha- nism into the safe position. As the barrel opens, pivoting on a fulcrum pin, the ?ring pin hammer is moved into the cooked position and the latch lock is allowed to move upward to retain the latch in the open position. The barrel pivots downward approximately 30? to the loading position until it rests against a stop located on the front end of the receiver. Insert a round into the chamber and close the barrel. As the barrel closes, its rear end depresses the latch lock, freeing the spring loaded latch which then pivots and locks the barrel to the receiver. Move the safety latch forward to expose the letter on the receiver. The weapon is then ready to be ?red. TAGO 27103 (3) b. T148333. TC 23?3 5 To reload after ?ring, repeat the unlocking cycle described in (1) above. This will cause the spring?loaded extractor to withdraw the spent case about 1 inch from the chamber. Pull the case the rest of the way from the chamber with either hand. Insert a new round as described in (2) above. The 3-round magazine 2) is loaded either before or after it is inserted into the weapon. (1) (3) (4) 6. Sights. To load the magazine outside the weapon, press each round forward into its chamber until the extractor round retainers lock over the base of the round. Insert the loaded magazine into the receiver from the right side of the launcher, pressing it against the driving spring, until the right chamber is alined with the barrel. A magazine retainer on the receiver keeps the magazine from being ejected. Move the safety from to F. To ?re the weapon, depress the safety device on the grip as you squeeze the trigger. When the rounds are loaded into the magazine, the rotating band of each projectile presses against a spring?loaded index- ing plunger on the underside of each chamber. As each round is ?red, the indexing plunger lever moves into the space vacated by the ?red projectile and the driving spring indexes the magazine to the right, alining the next chamber with the barrel. To remove the empty cartridge cases from the magazine chambers, depress the extractor releases with your ?ngers. The cases in the right and middle chambers are extracted and ejected from the right side of the weapon; the case in the third (left) chamber is extracted and ejected from the left side of the Weapon. To load the magazine when it is in the receiver, aline the third (left) chamber with the barrel and insert rounds in the ?rst and second (right and middle) chambers. Push the the magazine all the way to the left and insert a round into the third (left) chamber. The folding rear leaf sights of the XM79 and the T148E2 are calibrated to ranges of 75, 125, 225, 325, and 375. meters. Correct sight alinement is attained by positioning the front sight blade directly in the center of the notch 3). Large errors in de?ection can be corrected by moving the front sight blade to the right or left. TAGO 2710B TC 23?3 REAR LEAF SIGHT 125 A 75 Mr 4A BLADE Figure 3. Correct sight al?nement. Section AFAREUNITION 7. Description. a. General. The 404nm cartridge is ?xed?type ammunition with an impact?detonating fuze. The complete round consists of two major assemblies: the cartridge case and the projectile. - b. Cartridge case. The aluminum cartridge case is made with an integral propellant retainer. Into this retainer is inserted a thin- walled- brass cup which contains 330 milligrams of 81-mm mortar type propellant. An aluminum base plug which seals the back end of the cartridge case is then pressed and crimped into the prepellant retainer. Finally, an M42 percussion primer is pressed and crimped into the base plug. 6. OlaSSt?cet'ioa. The 40?min round is classi?ed in one of two categories: high explosive or practice. (1) The high explosive round consists of a grenade 1% inches in diameter containing approximately 1.25 ounces of explosive. The grenade is fermed of rectangular, wrapped steel Wire. The wire is notched at intervals to allow fragmentation on detonation. When the grenade detonates, fragments are distributed uniformly over the target area. The average initial velocity of the fragments is 4,800 fps. which makes them extremely lethal. TAGO 2710.3 TC 23?3 7 (2) The practice round is similar to the HE round except that the projectile is made of .067?inch thick steel. The space _in the grenade below the fuze booster is ?lled with yellow dye powder. When the projectile is detonated, the fuze booster breaks open the grenade and disperses the yellow powder as a smoke puff which is clearly visible at the maximum range. The practice round is used for ?ring practice and range determination. d. Fuses. The and T359E1 impact detonating fuzes are used with the HE and practice rounds. The 'maj or differences between the two fuzes are that the T333E1 arms on spin and is armed about 10 feet from the muzzle, whereas the T359E1 requires setback and spin to arm and arms 45 to 90 feet from the muzzle. When ?ring the XM381E1 or the XM382E2 in the grenade launcher, XM79 or T148E2, areas to the front and overhead must be free of obstructions from a distance of 10 feet from the ?rer to the target to prevent possible premature detonation of the projectile. e. ype rounds. Listed below are the type rounds available for the grenade launcher. Model Type length Fuzz Total weight XM381E1 HE 3.9 in 8 oz. XM406E1 HE 3.9 in 8 oz. XM382E1 _i Practice 3.9 in _i 8 oz. XM407E1 Practice 3.9 in 8 oz. (The major difference between the and the XM406E1 rounds and. between the X-M382E1 and XM407E1 rounds is the type of fuze.) f. Functioning. To ?re a projectile of the weight and caliber of these rounds a distance of 400 meters with uniform muzzle velocity, this weapon employs the high-low pressure propulsion system. When the ?ring pin strikes the primer, the primer ?ash ignites the propellant in the powder cup which burns, creating a pressure of 35,000 psi. in the high pressure chamber. The gas pressure ruptures the propel- lant cup at the eight vent holes and the gas then escapes into the low pressure chamber (interior portion of the cartridge case). Inside the low pressure chamber the propellant gases, at a pressure of 3,000 propel the projectile into the barrel where the ri?ing imparts a spin. The projectile leaves the launcher with a muzzle velocity Of 250 f.p.s. and a spin of 3,700 r.p.m. _This spin stabilizes the projectile in ?ight. Upon impact, the fuze functions and causes the projeC-tile to detonate. i 9. Effects. The XM381E1 and XM406E1 rounds are considered to have an e?ective casualty radius of approximately 15 feet againSt prone troops. Within the casualty radius, they have approximately TAGO 2710B TC 23.3 8 four times more casualty producing effect than other ammunition on a pound?for?pound basis. h. Recommended basic load. Individual armed Carried on Carried on battle Type with launcher unit trains group trains HEI 27 rounds- . 45 rounds i 45 rounds. Section IV. CAPABILITIES AND LIMITATIONS 8. Capabilities. A grenadier can place a lethal concentration of ?re in a target area from a range of 28 meters (30 yards), the maxi- mum arming distance of the T359E1 fuze, to 400 meters (435?440 yards) with either launcher. Due to the simplicity of loading and ?ring the launchers, he can cover several targets or target areas in a relatively short period of time. He can effectively engage vertical or point targets such as Windows or other openings in buildings, cave en- trances, openings in bunkers, and other similar targets at ranges up to 200 meters (220?230 yards). Point?target ?re of this type severely wounds or kills personnel occupying the position Without destroying the building or forti?cation. 9. Limitations. Due to the lethal radius of the HE rounds and the sighting system used with the launcher, a minimum range of 50 meters (54?55 yards) has been assigned this weapon for training. For com? bat, this minimum range may be reduced to 31 meters (33?34 yards) which is the maximum fuze arming distance. Thus, a unit?s close?in ?ghting capability is reduced by the limitations of the ?re of the launcher and by the reduction in the number of bayonets in the unit. Because of the minimum range, grenadiers also will be issued a pistol for close-in protection. (The launcher will be issued to individuals as a primary Weapon.) Section v. SAFETY PRECAUTIONS AND TECHNIQUE or FIRE 10. Safety precautions. Minimum troop safety limits must be prescribed because of the casualty radius of the HE rounds. For training, a limit of 39 meters (42?43 yards) is considered adequate for all tr00ps. For combat, this distance may be reduced to 31 meters (33?34 yards). 11. Technique of ?re. The primary mission of the grenade laUnch- ers is to incapacitate enemy personnel. a. Range determination. A grenadier should be able to accurately determine ranges to help increase his chance of obtaining a ?rst round hit on a target. The pattern of.burst of the projectile and the primary TAGO 271GB TC 23?3 9. mission of the weapon make ?rst round hits highly desirable though not mandatory for the accomplishment of the ?re mission. 6. Target Speed and lead determination. Dismounted enemy person- nel will be the primary target for the grenade launcher; nevertheless, speed and lead determinations will be an essential part of a grenadier?s training to enable him e?ectively to engage rapidly moving, mounted or dismounted, enemy personnel. c. Adjustment of ?re. Grenadier training should stress the im? portance of a ?rst round hit and the rapid adjustment of ?re to cover a target effectively. A grenadier strives for a ?rst round hit at all ranges. Since it is unreasonable to expect perfection in this respect, he must also learn to sense each round and make. corrections in range and de?ection tobring the next round on the target. d. Firing positions. Firing positions should provide cover, conceal- ment, observation, and ?elds of ?re consistent with the mission. The Weapon may be ?red from the standing, kneeling, or prone position. Ineo 2710B TC 23?3 10 CHAPTER 2 TACTICAL EMPLOYMENT Section I. INTRODUCTION 12. General. The introduction of the XM79 and T148E2 grenade launchers into the battle group weapons system increases the combat capability of the battle group in all forms of offensive and defensive combat and in its security Operations. This increase in combat capa- bility does not materially affect the tactical employment of the battle group so far as formations are concerned, but it gives subordinate elements a greater capability to operate over the frontages and depths prescribed in current doctrine. A primary effedt is the increased ability 'of the subordinate elements to accomplish their assigned missions rapidly. 13. Organization for employment. A launcher is assigned as a primary weapon to one man in each ?re team. He is called a grenadier. The weapons are employed in all phases of tactical operations. - Their principal role is the destruction of groups of enemy personnel. Other launchers are assigned to elements of the weapons platoon of the ri?e company and the ri?e company headquarters. Their principal role is to provide protection for weapon crews, command posts, and admin? istrative and logistical installations. Section II. OFFENSE 14. Mission. The mission of the launcher in offensive action is to destroy groups of enemy personnel and to provide close ?re support for assaulting elements after supporting artillery and mortar ?res have been lifted or shifted. 15. Ri?e company. a. As a result of the increased ?repower pro- vided by the launchers, the company commander may assign awider frontage to platoons and accept increased gaps between them during the attack. .Platoon frontages and the size of the gaps cannot be standardized; the company commander must determine both on the basis of the overall mission, the enemy situation, the terrain and weather, and the current strength of his company in each situation. 6. The capability to accept wider separation of platoons is based on the area ?re characteristic of the launcher at ranges from 50 meters (54?55 yards) to 400 meters (435 yards). With this capability, the platoon can provide its own close-in ?res similar to the ?res provided by supporting mortars and artillery. While the launchers are not TAGO 2710B we" .. TC 23?3 11 intended to replace the ?res currently available from supporting artillery and mortars, when communications with supporting ?re support elements are interrupted, the platoon can provide its own area ?re support and sustain itself in an isolated situation for a longer period. The company commander also may undertake more ambitious maneuvers; for example, a more distant separation of his maneuvering element from its ?re support element. 16. Ri?e platoon. a. The two launchers in the ri?e squad provide it with ?repower of a nature formerly available only from or through the platoon leader or company commander. The increase in ?repower increases the ?exibility of both the squad and the platoon because they may now maneuver their supporting weapons as an integral part of the squad. With the squad having an organic area ?re weapon, the platoon leader also may undertake more ambitious maneuvers. He may assign wider frontages to his squads and allow a greater separation of squads during maneuver. b. In the'attack, the platoon leader normally will allow his squad leaders freedom of action in the employment of their launchers. On occasion, he- may withdraw one or more of the weapons from within the platoon for employment in a support role. He will base his de- cision to take this action on the availability of ?elds of ?re and ?ring positions which will place the weapon within range of the objective. 17. Ri?e squad. The squad launchers give it an organic ?repower which was obtainable only from or through the platoon leader in the past. The ?re team leaders or the squad leader should control the ?res of the launchers to avoid indiscriminate ?ring on inappropriate targets. 18. Assault phase of the attack. The launchers are used in the assault to ?ll the gap in ?repower created when friendly supporting ?res are lifted from the objective area as the platoon closes on the objective. At this time, the launchers ?re at their maximum rate to ?x the enemy in his position. 19. Methods of employment in the attack. a. General. The direct ?re accuracy of the launcher is such that it can, within its range capability, continue to ?re on the objective after indirect supporting ?res have been lifted. During movement toward the objective, launchers normally will accompany the maneuvering elements. Once within range of the objective, they may be employed in an accom- panying role, employed in support of the assault from a ?xed position, or in a combination of these two methods. Primary considerations which govern the selection of the method of employment are the# (1) Range capability of the weapon. TAGO 27103 TC 23?3 12 (2) Availability of ?ring positions which provide observation and ?elds of ?re into the objective area. (3) Capability of the launchers to move with and ?re throughout the movement of the assaulting elements from the assault line to the objective. 6. Accompanying the assaalt elements. Since the launcher can be carried and ?red as easily as a ri?e, the grenadier has no dif?culty in keeping pace with the assaulting elements. This method of employ- ment- gives the ?re team leader close control of the grenadier, progres? sively reduces the range as the grenadier approaches the objective, thus increasing the accuracy of his ?re, and makes the launchers immediately available for employment during consolidation and reorganization. This is the method normally used because it provides the highest degree of close and continuous ?re support. 6. Supporting the assaultfrom a ?xed position. When the launchers are employed in a supporting role, their positions must be within range of the objective to permit- direct ?re. The squad and platoon leaders do not have continuous immediate control of the grenadiers that are supporting from ?xed positions and their launchers are not immedi? ately available to support the consolidation and reorganization. cl. Combination method of employment. A part of the squad?s (platoon?s) organic launchers may be employed in ?xed positions in a support role While the remainder accompany the assault elements. The advantages and disadvantages are as described in and above, but are in proportion to the number of launchers employed in each role. e. Consolidation and reorganization. The launchers are ideally suited to destroy or repel an enemy dismounted counterattack during the critical period of consolidation and reorganization. The launchers should be located Where they can best cover by ?re the likely avenues of enemy foot approach into the area. Section DEFENSE 20. Mission. The launchers normally are employed to cover by ?re the most liker avenues of enemy foot approach into the defensive position. (Since the most likely avenues of approach for a night attack may not be the same as those for a day attack, the launchers may have to be redeployed for the best coverage during hours of darkness.) Other missions may include ?lling gaps in the ?nal protective ?res of machineguns, reinforcing barrages and close-in concentrations, covering unoccupied gaps between units, and sup? porting a counterattack against enemy penetrations of- forward platoon areas. TAGO 2710B TC 23?3 13 21. Fire plans. a. The company commander directs the employ- ment of the company launchers only to the extent necessary to insure mutual support between forward elements of the company and between the company and adjacent units, and to insure protection for an exposed ?ank of the company. I). To implement the platoon defense plan, the platoon leader may select the general ?ring location and the principal direction of ?re for each of the platoon?s launchers. Squad leaders then select the exact ?ringpositions for their respective launchers and point out to each grenadier his principal direction and sector of ?re. As a general rule, the squad leader is allowed freedom of action in the employment of the launchers organic to his squad?the platoon leader directing their employment only to the extent necessary to insure a coordi? nated platoon ?re plan. 0. The normal frontage (100 meters i) assigned the ri?e squad in the defense and the range capability of the launcher permit mutual support between the two weapons organic to the squad. The sector of ?re assigned each launcher should overlap the sectors of adjacent launchers suf?ciently to insure complete coverage of the platoon area. The principal direction of ?re covers the most likely avenue of enemy foot approach into the area. 22. Selection of ?ring positions. Launchers are employed along the same general line as other weapons of the platoon. Firing posi- tions should be selected which provide maximum cover and conceal- ment for the grenadier consistent with the assigned mission. Extreme care must be taken to insure that ?elds of ?re are cleared of obstructions which might cause premature detonation of the projectile. Alternate and supplementary positions are selected for each weapon. 23. Control measures. - The launchers are located within the squad defense area where they can best accomplish the assigned mission. Each ?re team leader places himself where he can best control the ?res of his grenadier and be in a position to operate the launcher if the grenadier becomes a casualty. 24. Conduct of the defene. As the enemy continues his advance toward the defensive position, he is brought under an ever?increasing volume of ?re from those direct and indirect ?re weapons located within the battle area. However, in order to gain an element of surprise against the enemy, the platoon leader may direct thata por- tion or all of the launchers withhold their ?re until the enemy reaches a speci?ed location, and then order all launchers to open ?re simul? taneously. This surprise ?re, in conjunction with the ?res of other platoon weapons, will have a devastating e?ect upon the enemy, particularlyin the assault phase of the attack. If no restriction is TAGO 271013 TC 23?3 placed on the ?ring of the launchers, the grenadiers engage appropriate targets within their sectors as soon as they come within range. Fire team leaders insure that the grenadiers engage targets appropriate to the launcher. When ?nal protective ?res are called for, the grenadiers engage the largest mass of enemy foot elements within their assigned sectors or, if they have been assigned the mission of ?lling the gaps in ?nal protective ?res of other weapons, they commence ?ring on their assigned gaps. By Order of We'Zber M. Breaker, Secretary of the Army: Of?cial R. V. LEE, Major Generaz, United States Army, The Adjutant G'e-nemz. Distribution Active Army: DCSPER (3) ACSI (3) DCSOPS (3) DCSLOG (3) ACSRC (3) Tech Stf, DA (2) Tech es Bd (2) USCONARC (15) US ARADCOM (5) USA Arty Bd (2) USA Armor Bd (2) USA Abn Elct Maj Oomd (5) OS Base Comd (3) hrti (2) I Colleges (5) G: None. USAR: None. G. H. DECKER, - Generaz, United States Army: Chief of Sta?'. Br (5) Armies (10) Corps (5) Div (5) except Armd Div (20) (5 ea CC) Inf Bg (5) Armd Bn (3) Inf Co (2) Armd Co (2) Abn Co (2) Units organized under following 7?11 (5) 7?25 (3) 7?31 (5) 17415 (3) 17?51 (5) 17?55 (3) For eXplanation of abbreviations used, see AR 320?50. TAGO 27103 (LS, GOVERNMENT PRINTING OFFICE: ISED