Yamaha K-31 Service Manual

NOTES: Disclaimer: Manual readers assume all responsibility for application of information provided in this manual. Though the translation has been

10 Figure 2 B. Mq. Mod 11 A. Mq Mod 31 1. Front sight housing 3. Mounting Sleeve 2. Rear Sight The interior of the barrel h

11 Figure 3 B. Mq. Mod 11 A. Mq. Mod 31 1. Front Sight Blade 4. Front Sight Housing 2. Groove

12 Figure 4 Rear Sight A. Mq. Mod 31 1. Elevation Adjustment Slide 2. Sight Leaf 3. Rear Sight Slot 4. Sight Housing 5. Slide Stop Front S

13 Figure 5 Rear Sight B. Mq. Mod 11 1. Rear Sight Base 2. Elevation Adjustment Slide 3. Sight Leaf 4. Rear Sight Slot 5. Slide Stop

14 and 15 Figure 6 A. Mq. Mod 31 I. Armed 1. Bolt with firing mechanism 2. Loading Slot 3. Barrel 4. Receiver 5. Magazine Slot 6. Trigger

16 and 17 Figure 7 B. Mq. Mod 11 I.Armed 1. Bolt with firing mechanism 2. Loading Slot 3. Barrel 4. Receiver 5. Magazine Slot 6. Trigger Mec

18 Figure 8 Cam Follower A. Mq. Mod31 B. Mq Mod 11 1. Cam follower pin 2. Cam follower handle The inner part of the

19 Figure 9 A. Mq. Mod 31 B. Mq. Mod 11 1. Extractor 2. Cam follower pin slot 3. Extractor groove 4. Cylinder 5. Attachment l

20 Figure 10 Locking Sleeve A. Mq. Mod 31 B. Mq Mod 11 1. Locking Lugs 2. Helical Slot b) for Model 11 : only the rear part o

21 The cam follower pin slides in the helical slot in the locking sleeve and makes the locking sleeve turn when the bolt is opened or closed. It is

1 Inside Cover Swiss Army No. 53.101 f Rifle (Model 11, Model 31, Scoped Model 31/42, 31/43 and 55) 1958

22 Fig. 11 Firing Mechanism A. Model 31 1. Firing Pin 5. Bolt Plug 2. Firing Pin Spring 6. Safety Slot 3. Cocking Piece 7. Cam Fol

23 Fig. 12 Firing Mechanism B. Mq. Model 11 1. Firing Pin 5. Bolt Plug 2. Firing Pin Spring 6. Safety Slot 3. Cocking Piece 7. Ca

24 Fig. 13 B. Mq. Model 11 A. Mq. Model 31 1. Magazine Plate 3. Magazine Case 2. Magazine Spring 4. Magazine Stop

25 Fig. 14 Hardware A. Mq. Model 31 B. Mq. Model 11 1. Sling Loop 1. Sling Loop 2. Sling Hook 2. Sling Hook 3. Stacking Hook

26 Fig. 15 Model 18 Bayonet with Sheath 1. Blade 2. Hand Guard 3. Hilt 4. Sheath

27 Fig. 16 Accessory Pouch 1. Grease Can 2. Grease Can Lid 3. Chamber Mirror 4. Cleaning Cord 5. Accessory Pouch 6. Grease Can 7. Chamber Cle

28 III. Disassembly and Reassembly 1. Weapon Disassembly 4 Before disassembly it is important to check for and remove all cartridges by inspectin

29 d) Disassembly of the firing mechanism -Compress the firing pin spring -Remove the firing pin, the firing pin spring and the bolt plug. e) Disas

30 and 31 Mq. 11 To remove the hand guard; it is necessary to raise the rear sight leaf to a 90 degree angle, then carefully lift the hand guard tur

32 and 33 b) Bolt Mq. 11 Mq. 31 Replace the Extractor Slide the locking sleeve, lugs forward, over the cylinder Replace the cocking piece and s

2 Approved on order of the Federal Military Department Bern, 5.2.58 Chief of Instruction Preliminary Remarks

33 (cont) and 34 3. Disassembly and Assembly of the Magazine 8 The magazine should only be rarely disassembled. Perform only if the Magazine is ve

35, 36 IV. Function 1. Trigger Mechanism and Rifle Discharge (Fig. 17) 11 When the weapon is ready to fire, the bolt is closed and locked, the

37 Fig. 18 A. Mq. Mod. 31 1. Locking Lugs 2. Barrel 3. Cam follower plate 4. Receiver 5. Locking Lug slots

38 and 39 13 During locking sleeve rotation, the locking lugs exit the locking lug slots in the receiver and stop rotation at the entrance of the lo

40 and 41 or c) If the bolt cannot be opened: -Remove the magazine, -Place the cocking piece sear between the safety slot and the firing slot in the

42, 43 and 44 VI. Weapon Maintenance 1. Overview 22 Each shooter is responsible for the maintenance of his rifle. The Group and Section Chiefs

44 (cont), 45 and 46 29 Barrel cleaning is performed by means of a cleaning cord, after having removed the bolt and the magazine. For Mq. 31 the lo

46 (cont), 47 34 If a major inspection is required, contact the responsible officers. A major inspection should take place at least one time during

48,49 VII. Scoped Rifles A. Scoped rifles 1931/42 and 1931/43 1. Overview 35 There are two Model 31 Scoped rifles: - Model 31/42, scope power

50 Fig. 19 Scoped Rifle 31/42 and 31/43 With objective in view position 1. Scope housing 2. Mobile objective 3. Sight leaf 4. Elevation slide

3 b) The following will receive service copies for the command archives - To all Army units , Border Brigades, Fortress Brigades and Redoubt Briga

51, 52 and 53 After shooting, the mobile objective must be lowered into its slot in the stock and lower the elevation slide to 1. If the objective r

53 cont, 54 Additional information 40 The scope can be removed. A bayonet can be mounted to the barrel. The rifle can be aimed with the iron sight

55, 56 Fig. 24 1. Bolt plug 2. Cocking piece 3. Cam follower plate 4. Locking sleeve 5. Cylinder 6. Firing pin 7. Firing pin spring 8. Sl

57,58 For the scoped rifle, it is important to pay attention to the following points: Use the weapon with care to avoid impacts, wet and dirty condit

59, 60 Fig. 27 29 Countersunk screws for windage adjustment (loosen 1 turn) 30 Elevation knob 31 Focus ring 4. Sight adjustment pro

61, 62 For this reason; one should not, as a general rule, adjust the knobs unless the impact point is at least 0.5 0/00 off center or is at least 15

63,64 a) Supports The fundamental rule for shooting, sitting and standing, is to put the left side of the body forward and in general support the b

65 Fig.28 Method for gauging fie ld targets at distances of 100, 300 and 500 m

66, 67 The shooting program should contain the exercises mentioned the Chapter 8 and can be developed according the circumstances. Where it is not po

68, 69 Part 2 Munitions I. Overview 47 Ammunition for long rifle, musketoon (short rifle), Automatic rifle, and machine gun are delivered to troo

4 Table of Contents Section Part 1: Weapon Description 1-37 I. Overview II. Parts and Accessories 2-3

70, 71 Common Bullet 11 Armor Piercing Bullet Tracer Bullet Bullets Common Cartridge Armor Piercing Cartridge

72, 73 Exterior Characteristics: No color code on the base of the cartridge. 2. Armor Piercing Cartridge 50 The armor-piercing bullet is similar i

74, 75 Fig. 31 Handling Blank Rifle Blank Automatic Blank Machine Gun Cartridge Cart

76, 77, 78 V. Packaging 56 The charger with 6 cartridges and the package of 10 cartridges are the smallest available Packages. Packaging Details:

78 cont, 79 60 When choosing a storage location, an uninhabited and isolated place should be chosen, if possible. Good storage locations for muniti

81, 82, 83 -Place the left thumb over the loading slot (fig. 36) -Open the bolt with the right hand, and push the exposed cartridge downward into th

83 (cont), 84 While bringing the weapon to the shoulder, the shooter will calmly inhale and exhale, set the rear sight in one click, hold his breath,

85, 86, 87, 88 Every rifle has it’s own aim point, that can vary depending on the eye of the shooter, the resolution of the target as well as other fa

88 (cont) -When shooting toward or over friendly troops, the friendly troops should not be more than 100m from the weapon and in all cases at a s

90, 91 Appendix I Training Figures Fig.34 Loading: Inserting the Charger Fog. 35 Loading: Inserting the Charger

5 6. Training 45 7. Safety Measures 46 8. Shooting Program - Part 2: Ammunition I. Overview 47

92, 93 Fig.36 Removing cartridges: Opening the Bolt Fig. 37 Removing cartridges: Replacing the cartridges in the charger

94,95 Fig. 38 Prone Position Fig. 39 Standing Position: Rapid fire

96, 97 Fig. 40 Standing Position with body support Fig. 41 Rapid Fire from the hip while marching

98, 99 Fig. 42 Prone Position with support Fig. 43 Co mbat position on a slope with the elbow on a shovel

100, 101 Fig. 44 Example of a kneeling position Fig. 45 Standing position behind a tree

102, 103 Fig. 46 Shooting position in a tree Fig. 47 Sitting Position

104, 105 Appendix II Tables Table 1 Trajectory Danger Zones in meters (Aim point = Target center) Target Height in m Elevation Target head .33m K

106, 107 Table 5 Aim Point Weapon Shot Distance Elevation Setting Aim point lower than the shot Mod. 11 100m 200m 300m 300 300 300 30 cm 40 cm 30

108, 109 Appendix III Order of the Federal Military Department Concerning Ammunition (10 April 1951) 1. The following are considered munitions -Ball

110, 111 Appendix IV Instructions for avoiding Small Arms Damage Avoid Weapon Damage! Shooting foreign ammunitions or non-issued ordnance with y

6 Technical Information Weapon: Rifle 11 Rifle 31 Barrel Length in mm 592 652 Caliber in mm 7.54 7.51

112, 113 1. How do you avoid barrel bulging? -Never plug the barrel of your rifle with cleaning patches or grease. -Ensure no dirt or snow get

114,115 Shooting with a blocked barrel will cause a barrel bulge Bulged Barrel Fractured Bulge Blocked, exploded barrel Exploded Barrel Before ea

116, 117 The barrel must be replaced if it is bulged 2. Take care of your weapon! Manage your weapon to ensure wise treatment and proper handlin

118, 119 Take care of your parts! Incorrect Correct Broken Cam If you shoot when the handle is not all the way forward, y

120, 121 Losing a Magazine! Loss of a magazine due to poor placement in the weapon. When inserting a magazine into your weapon, check

122, 123 Sear adjustment Troops in the field are prohibited from adjusting or tampering with the rifle sear. Only gunsmiths may adjust the sear of a

124, 125 Stock disassembly for the Mod. 11 Removing the hand guard WRONG Correct Do not forget to raise the sight leaf vertica

126, 127 3. Cleaning and greasing the barrel -Take care of the barrel of your rifle and avoid oxidation by proper cleaning and greasing. -After ea

128, 129 Take care of your cleaning cord! WRONG! Without the locking sleeve, the cord will snag on the ejector as it passes Correct! Insert

130, 131 Ovalization of the muzzle Using this cleaning method will ovalize the muzzle of your barrel. A barrel with an ovalized muzzle, loses its

7 and 8 Part I Weapon Description I. Overview 1 The rifle (model 11 and model 31) is the soldier’s personal arm that he uses as a precision arm for

132, 133 4. Shooting with a reducer tube If you fired the weapon with a reducer tube, Please note the following points: -Upon completion of shooti

134, 135 5. Using the Muzzle Cover -Protect the rifle barrel with a muzzle cover. -Aside from issued muzzle covers, other cover are authorized for

136, 137 Weapons where the impact point is offset should be sighted in. Sighting in is a gunsmith’s job The gunsmith has in his equipment, several

9 Fig. 1 A. Mq. Mod 31 B. Mq. Mod 11 1. Bolt with firing mechanism 3. Receiver 2. Sights 4. Hand Guard 5. Barrel 6.