U.S. Army Materiel Command pamphlet. Guns series. Automatic weapons. АМСР 706-260

347 Pages·16.368 MB·English

HEADQUARTERS
AMC PAMPHLET UNITED STATES ARMY MATERIEL COMMAND
No. 706-260 WASHINGTON. D. C. 20315 5 February 1970
ENGINEERING DESIGN HANDBOOK
AUTOMATIC WEAPONS
Paragraph Page
LIST OF ILLUSTRATIONS \i
LISTOFTABLES viii
LIST OF SYMBOLS x
PREFACE xviii
CHAPTER 1. INTRODUCTION
1-1 SCOPE AND PURPOSE 1-1
1-2 GENERAL 1-1
1-3 DEFINITIONS 1-1
1-4 DESIGN PRINCIPLES FOR AUTOMATIC WEAPONS 1-1
CHAPTER 2. BLOWBACK WEAPONS
2-1 GENERAL 2-1
2-2 SIMPLE BLOWBACK 2-3
2-2.1 SPECIFIC REQUIREMENTS 2-3
2-2.2 TIMEOFCYCLE 2-4
2-2.2.1 Recoil Time 2-5
2—2.2.2 Counterrecoil Time 2-6
2-2.2.3 Total Cycle Time 2-7
2-2.3 EXAMPLE OF SIMPLE BLOWBACK GUN 2-8
2-2.3.1 Specifications 2-8
2—2.3.2 Computed Design Data 2-8
2—2.3.3 Case Travel During Propellant Gas Period 2-10
2-2.3.4 Sample Problem of Case Travel 2-10
2—2.3.5 Driving Spring Design 2—11
2-3 ADVANCED PRIMER IGNITION BLOWBACK 2-12
2-3.1 SPECIFIC REQUIREMENTS 2-12
2-3.2 SAMPLE CALCULATIONS OF ADVANCED
PRIMER IGNITION 2-13
2-3.2.1 Firing Rate 2-13
2—3.2.2 Driving Spring Design 2—15
2^1 DELAYEDBLOWBACK 2-17
2-4.1 SPECIFIC REQUIREMENTS 2-17
2-4.2 DYNAMICS OF DELAYED BLOWBACK 2-18
2-4.3 SAMPLE PROBLEM FOR DELAYED
BLOWBACK ACTION 2-24
2-4.3.1 Specifications 2-24
2-4.3.2 Design Data 2-24
2-4.4 COMPUTER ROUTINE FOR COUNTERRECOILING
BARREL DYNAMICS 2-33
2-4.5 SPRINGS 2-37
2-4.5.1 Driving Spring 2-37
2-4.5.2 Barrel Spring 2-39
2-4.5.3 Buffer Spring 2-39
2-5 RETARDEDBLOWBACK 2-40
2-5.1 SPECIFIC REQUIREMENTS 2-40
AMCP 706-260
TABLE OF CONTENTS (Con't.)
Paragraph Page
2-5.2 DYNAMICS OF RETARDED BLOWBACK 2-40
2—5.2.1 Kinematics of the Linkage 2—40
2-5.2.2 Equations of Dynamic Equilibrium 2—43
2—5.2.3 Digital Computer Program for
the Dynamic Analysis 2—44
2-6 RATING OF BLOWBACK WEAPONS 2-47
CHAPTER 3. RECOIL-OPERATED WEAPONS
3-1 GENERAL 3-1
3-2 LONG RECOIL DYNAMICS 3_i
3-3 SAMPLE PROBLEM _LONG RECOIL MACHINE GUN .. 3-1
3-3.1 SPECIFICATIONS 3_1
3-3.2 DESIGNDATA 3-1
3-4 SHORT RECOIL DYNAMICS 3_9
3-5 SAMPLE PROBLEM _SHORT RECOIL MACHINE GUN . . 3-9
3-5.1 SPECIFICATIONS 3_9
3-5.2 DESIGNDATA 3-9
3-6 ACCELERATORS 3_15
3-7 SAMPLE PROBLEM ACCELERATOR 3-17
3-7.1 SPECIFICATIONS 3-17
3-7.2 DESIGNDATA 3-17
3-8 RATING OF RECOIL-OPERATED GUNS 3-21
CHAPTER 4. GAS-OPERATED WEAPONS
4-1 GENERALREQUIREMENTS 4-1
4-2 TYPES OF GAS SYSTEMS 4-1
4-3 CUTOFF EXPANSION SYSTEM 4-1
4-3.1 MECHANICS OF THE SYSTEM _i
4
4—3.1.1 Gas Filling Period 4_g
4-3.1.2 Bolt Locking Cam 4_9
4—3.1.3 Cam Curve 4—15
4-3.2 SAMPLE PROBLEM FOR CUTOFF EXPANSION
SYSTEM 4-17
4—3.2.1 Specifications 4—17
4—3.2.2 Design Data, Computed 4—17
4—3.2.3 Counterrecoil Computed Data 4—19
4-3.2.4 Counterrecoil Time 4_20
4-3.2.5 Recoil Time 4-23
4-3.2.5.1 Recoil Time, Decelerating 4—23
4-3.2.5.2 Recoil Time, Accelerating 4—24
4-3.3 DIGITAL COMPUTER ROUTINE FOR CUTOFF
EXPANSION 4-28
4-3.3.1 Gas Dynamics Before Cutoff 4-28
4—3.3.2 Gas Dynamics After Cutoff 4—29
4-3.3.2.1 Bolt Unlocking During Helix Traverse 4-29
4-3.3.2.2 Bolt Unlocking During Parabola Traverse 4-29
4-3.3.2.3 Bolt Unlocked, Bolt Traveling With
Operating Rod 4—31
AMCP 706-260
TABLE OF CONTENTS (Con't.)
Paragraph Page
4—3.3.3 Dynamics After Gas Cylinder Operations 4-32
4-3.3.3.1 Recoil Dynamics 4-32
4-3.3.3.2 Counterrecoil Dynamics 4-35
4-3.3.3.3 Bolt Locking Dynamics 4-36
4-3.3.3.4 Firing Rate 4-37
4-3.4 SPRINGS 4-37
4-3.4.1 Driving Spring 4-37
4-3.4.2 Buffer Spring 4-37
4-4 THE TAPPET SYSTEM 4-38
4-4.1 SAMPLEPROBLEM 4-38
4-4.1.1 Specifications 4-38
4-4.1.2 Preliminary Design Data 4-38
4-4.1.3 Design Data. Computed 4-38
4-4.1.4 Spring Design Data 4-45
CHAPTER 5. REVOLVER-TYPE MACHINE GUNS
5-1 SINGLE BARREL TYPE 5-1
5-1.1 PRELIMINARY DYNAMICS OF FIRING CYCLE 5-2
5—1.1.1 Sample Problem of Preliminary Firing Rate Estimate . . . 5-7
5-1.1.2 Analysis of Cam Action 5-8
5-1.1.2.1 Sample Calculation of Cam Action 5-14
5-1.1.2.2 Driving Spring 5-18
5_1.2 FINAL ESTIMATE OF THE COMPLETE FIRING CYCLE 5-18
5—1.2.1 Control of Recoil Travel During Propellant Gas Period . . 5-20
5-1.2.2 Operating Cylinder Design 5-23
5—1.2.3 Dynamics of Simultaneous Adapter-operating
Cylinder Action 5-31
5 — 1.2.4 Sample Calculation for Complete Firing Cycle 5-32
5-1.2.4.1 Counterrecoil Time of Recoiling Parts 5-33
5-1.2.4.2 Digital Computer Analyses of Barreldrum Dynamics . . . 5-37
5-1.2.4.3 Firing Rate Computation 5-39
5-2 DOUBLE BARREL TYPE 5-46
5-2.1 FIRINGCYCLE 5-46
5-2.1.1 Cam Function 5-46
5-2.1.2 Loading and Ejecting 5-48
5-2.1.3 Ammunition Feed System 5—48
5-2.2 DYNAMICS OF FIRING CYCLE 5-49
5-2.2.1 Cam Analysis 5-50
5-2.2.2 Energy Concept 5-52
5-2.2.3 Digital Computer Program for Firing Cycle 5-52
CHAPTER 6. MULTIBARREL MACHINE GUN
6-1 GENERAL 6-1
6-2 BOLT OPERATING CAM DEVELOPMENT 6-1
6-2.1 CAMACTION 6-1
6—2.1.1 Cam Kinematics 6-3
6-2.1.2 Definition of Symbols 6-4
6—2.1.3 Cam Forces 6—5
6—2.1.4 Locking Angle 6-6
AMCP 706-260
TABLE OF CONTENTS (Con't.)
Paragraph Page
6-2.2 ROTOR KINEMATICS 6-7
6-2.3 ILLUSTRATIVE PROBLEM 6-9
6-2.3.1 Cam Analysis During Feed, Rotor at Constant Velocity .. 6-9
6-2.3.2 Cam Analysis During Ejection, Rotor at Constant
Velocity 6-11
6—2.3.3 Cam Analysis During Rotor Acceleration 6—12
6-2.3.4 Digital Computer Program for Gun Operating Power .... 6-13
6-3 RATING OF GAS-OPERATED AND EXTERNALLY
POWEREDGUNS 6-14
CHAPTER 7. COMPONENT DESIGN
7-1 GENERAL 7-1
7_2 FEED MECHANISM DESIGN 7-1
7-2.1 MAGAZINES 7-2
7—2.1.1 Box Magazines 7-2
7-2.1.2 Box Feed System 7-4
7-2.1.2.1 Flat Tape Spring 7-5
7-2.1.2.2 Rectangular Coil Spring 7-6
7—2.1.3 Example Problems 7-6
7-2.1.3.1 Flat Tape Spring 7-7
7-2.1.3.2 Rectangular Coil Spring 7-8
7-2.2 BOLT-OPERATED FEED SYSTEM ?-9
7_2.3 ROTATING FEED MECHANISM 7-10
7-2.3.1 Recoil-operated Feed Mechanism 7-10
7-2.3.2 Electrically Driven Feed Mechanism 7-12
7_2.4 LINKLESSFEED SYSTEM 7-14
7—2.4.1 Power Required 7-19
7-2.4.2 Example Problem for Power Required 7-21
7-3 EXTRACTORS, EJECTORS, AND BOLT LOCKS 1~24
7-3.1 EXTRACTORS 7~24
7_3.2 EJECTORS 7-27
7_3 2.1 Ejector Dynamics 7-27
7-3.2.2 Sample Problem of Ejector Dynamics 7-27
7-3.3 BOLTLOCKS 7-30
7_4 FIRING MECHANISM 7-32
7_4.1 COMPONENTS, TYPES, AND ACTION 7-32
7-4.1.1 Trigger Pull 7-37
7_4 12 Firing Pin Design 7-39
_5 ' LINKS •. . . . 7-39
7
7_5 i TYPES OF LINK 7-40
7_s'.2 DESIGN REQUIREMENTS 7-40
7-6 MOUNTS 7-44
7_6.1 GEOMETRY AND RESOLUTION OF FORCES 7-44
7-6.2 SAMPLEPROBLEM 7-48
CHAPTER 8. LUBRICATION OF MACHINE GUNS
3-1 GENERALCONCEPT 3-1
3-2 EXAMPLES OF LUBRICANTS 8-1
8-3 CASELUBRICANT 8~2
IV
AMCP 706-260
TABLE OF CONTENTS (Con't.)
APPENDIXES
No. Title Page
A-1 Flow Chart for Delayed Blowback A-1
A—2 Listing for Delayed Blowback Program A—4
A-3 Flow Chart for Retarded Blowback A-6
A^l Listing for Retarded Blowback Program A—9
A—5 Flow Chart for Cutoff Expansion A—12
A-6 Listing for Cutoff Expansion Program A—15
A-7 Flow Chart for Operating Cylinder A-20
A-8 Listing for Operating Cylinder Program A—22
A—9 Flow Chart for Cam and Drum Dynamics During Recoil . . A—26
A—10 Listing for Cam and Drum Dynamics During Recoil A—30
A—1 1 Flow Chart for Cam and Drum Dynamics During
Counterrecoil A—35
A—12 Listing for Cam and Drum Dynamics During
Counterrecoil A—38
A—13 Flow Chart for Double Barrel Machine Gun A—43
A—14 Program Listing for Double Barrel Machine Gun A—46
A-15 Flow Chart for Multibarrel Power A-52
A—16 Program Listing for Multibarrel Power A—59
B Automatic Control of Rounds in a Burst for
Weapon Effectiveness B— 1
GLOSSARY G-l
REFERENCES R-1
AMCP 706-260
LIST OF ILLUSTRATIONS
Fig. No. Title Page
2—1 Typical Pressure-time Curve 2—1
2—2 Schematic of Simple Blowback Mechanism 2—3
2—3 Allowable Case Travel 2—4
2—4 Pressure-time Curve of Cal .45(11.42 mm) Round 2—8
2—5 Schematic of Advanced Primer Ignition System 2—13
2—6 Locking System for Delayed Blowback 2—18
2—7 Pressure-time Curve of 20 mm Round 2—25
2—8 Schematic of Retarded Blowback Linkage 2—40
2—9 Kinematics of Retarded Blowback Linkage 2—41
2—10 Dynamics of Bolt and Linkage 2—42
3—1 Schematic of Long Recoil System 3—2
3—2 Schematic of Short Recoil System 3—2
3_3 Accelerator Geometry 3 — 16
4—1 Impingement System 4_i
4_2 Cutoff Expansion System 4_2
4-3 Rotating Bolt Lock and Activating Cam 4-11
4-4 Force System of Bolt Cam 4-12
4_5 Pressure-time Curve of 7.62 mm Round 4—18
4_6 Operating Distances of Moving Parts 4—19
4_7 Tappet System 4-38
4_8 Pressure-time Curve of 7.62 mm Carbine Round 4^10
5—1 Schematic of Single Barrel Revolver-type Machine Gun .... 5—1
5_2 Two Stage Ramming 5_2
5—3 Force Diagram of Recoiling Parts and Slide 5—3
5_4 Schematic of Cam Geometry 5—5
5_5 Cam-slide Force Diagrams 5—9
5—6 Single Barrel Drum Loading Diagram 5—10
5_7 Single Barrel Drum Dynamics 5—11
5-8 Interior Ballistics of 20 mm Revolver-type Gun 5-19
5_9 Extractor Assembly With Antidouble Feed Mechanism .... 5—35
5—10 Extractor Cam Assembly 5—36
5—11 Location of Basic Operations 5—47
5—12 Schematic of Double Barrel Drum-cam Arrangements 5—47
5—13 Schematic of Ammunition Feed System 5—48
5—14 Schematic of Ammunition Magazine 5—49
5—15 Double Barrel Cam Force Diagrams 5—50
5_16 Double Barrel Drum Loading Diagram 5—51
5—17 Double Barrel Drum Dynamics 5—51
5—18 Force-time Curve of 20 mm Revolver-type Gun 5—53
5—19 Geometry of Cam Actuating Lever 5—55
6—1 Cam Contour of Multibarrel Gun 6—2
6—2 Loading Diagram of Bolt and Cam During Acceleration . . . 6—2
6_3 Feed Portion of Cam 6—3
6—4 Loading Diagram of Bolt and Cam During Deceleration . . . 6—7
6—5 Bolt Position Diagram for Computer Analysis 6—13
AMCP 706-260
LIST OF ILLUSTRATIONS (Con't.)
Fig. No. Title Page
7-1 Initial Contact of Bolt and Cartridge Case Base 7_i
7-2 Chamber-projectile Contact 7-2
7-3 Box Magazine 7-2
7-4 Lip Guides 7_3
7-5 Lip-cartridge Case Orientation 7—4
7-6 Geometry of Double Row Stacking 7_4
7—7 Box Magazine Follower 7—4
7-8 Flat Tape Spring and Loading Analogy 7_5
7-9 Rectangular Coil Spring and Loading Characteristics 7_7
7-10 Schematic of Feed System. End View 7-10
7-11 Feed System Illustrating Mechanics of Operation 7-11
7-12 Recoil-operated Rotating Feed Mechanism 7-13
7-13 Feed Wheel and Operating Lever Units 7-14
7-14 Electrically Operated Rotating Feed Mechanism 7-15
7-15 Outer Drum 7-16
7-16 Inner Drum Helix 7-16
7—17 Conveyor Elements 7-17
7-18 Schematic of Linkless Feed System 7-18
7-19 Path of Rounds in Single End System 7-19
7-20 Extractors 7-25
7-21 Extractor Loading Diagrams 7-26
7-22 Ejectors 7-28
7—23 Ejector Loading Diagram 7-29
7-24 Sliding Breech Lock 7_31
7-25 Tipping Bolt Lock 7-32
7-26 Firing Mechanism for Recoil Machine Gun 7—33
7-27 Firing Mechanism for Gas-operated Machine Gun 7-34
7—28 Three-position Firing Mechanism 7-36
7-29 Triggering Mechanism Loading 7-38
7-30 Ammunition Link. Cal .50 Round 7_4l
7-31 Nose Fanning Flexibility. 7.62 mm Link 7—42
7—32 Base Fanning Flexibility. 7.62 mm Link 7—43
7-33 Geometry of Base Fanning 7—44
7-34 Helical Flexibility. 7.62 mm Link 7-45
7-35 Total Folding 7.62 mm Ammunition Belt 7-46
7-36 Partial Folding 7.62 mm Ammunition Belt 7-46
7-37 Loading Link With RADHAZ Shield 7_47
7—38 Loading Diagram of Mount 7-47
B—1 Hit Probabdity vs Number of Rounds in a Burst B—2
AMCP 706-260
LIST OF TABLES
Table No. Title Page
2- 1 Case Travel of Cal .45(11.42 mm) Gun 2-11
2-2 Recoil Travel of 20 mm Gun 2-26
2-3 Symbolcode Correlation for Delayed Blowback Program .. 2-36
2-4 Input for Delayed Blowback Program 2-37
2-5 Counterrecoil Dynamics of Delayed Blowback Gun 2-38
2-6 Symbolcode Correlation for Retarded Blowback 2-46
2-7 Input Data for Retarded Blowback 2-47
2-8 Retarded Blowback Dynamics 2-48
3-1 Recoil Travel of 20 mm Gun 3-3
3-2 Spring Design Data of Recoil-operated Guns 3-8
3-3 Recoil Travel of 20 mm Gun Equipped With Accelerator .. 3-17
4-1 Computed Dynamics of Gas Cutoff System 4—25
4-2 Gas Expansion Time Calculations 4-29
4-3 Symbolcode Correlation for Cutoff Expansion 4—30
4-4 Input for Cutoff Expansion Program 4-31
4-5 Computed Dynamics Before Gas Cutoff 4-32
4-6 Computed Dynamics After Gas Cutoff Bolt Unlocking
During Helix Traverse 4-33
4-7 Computed Dynamics After Gas Cutoff Bolt Unlocking
During Parabola Traverse 4-33
4-8 Computed Dynamics After Gas Cutoff Bolt
and Rod Unit Recoiling After Cam Action 4-34
4-9 Computed Dynamics. Counterrecoil Bolt Locking
During Parabola Traverse 4-35
4-10 Buffer Spring Design Data 4-39
4_11 Dynamics of Tappet 4-43
4_12 Critical Pressure Time Requirements 4-46
5—1 Free Recoil Data of 20 mm Revolver-type Machine Gun ... 5—21
5-2 Preliminary Recoil Adapter Data 5-22
5_3 Revised Preliminary Recoil Adapter Data 5-24
5-4 Operating Cylinder Data for 0.12 in.2
Orifice (Critical Pressure) 5-26
5-5 Operating Cylinder Data for 0.12 in.2 Orifice 5-27
5-6 Operating Cylinder Data for 0.09 in.2 Orifice 5-28
5-7 Operating Cylinder Data for 0.06 in.2 Orifice 5-29
5_8 Symbolcode Correlation for Operating Cylinder 5-37
5-9 Symbolcode Correlation for Cam Dynamics 5-38
5_10 Input Data for Drum Dynamics During Recoil 5-38
5-11 Input Data for Drum Dynamics During Counterrecoil .... 5-39
5-12 Computed Recoil and Operating Cylinder Data for
Orifice Area of 0.042 in.2 5-40
5-13 Cam and Drum Dynamics During Recoil 5-41
5-14 Cam and Drum Dynamics During Counterrecoil 5-42
5_15 Symbolcode Correlation for Double Barrel Machine Gun .. 5-56
5-16 Input Data for Double Barrel Machine Gun 5-56
5-17 Double Barrel Machine Gun Dynamics 5—59
VII
AMCP 706-260
LIST OF TABLES (Con'f.)
Table No. Title Page
«5-1 Symbolcode Correlation of Variables for
Multibarrel Gun 6-14
6-2 Symbolcode Correlation and Input for Gun Operating
Power 6-15
6-3 Cam Dynamics 6-16
6-4 Gun Operating Power 6-17
7-1 Power Required for Linkless Belt Feed System 7-24
7-2 Firing Pin Dynamics 7-40