Some Comments Regarding Performance Potential for a New Machine Gun and Ammunition Concepts

1. Some Comments Regarding Performance Potential for a New Machine Gun and Ammunition Concepts Abe Flatau Consultant

2. General Outline • Summary • Introduction • Brief Technical Overview • Ammunition • Emphasis on lightweight, high V0, very low drag projectiles = high kinetic energy to deposit on target • Brief Comparison of Trajectory Profiles • Proposed vs. current

3. Conclusion • It is strongly recommended that the key technologies be brought together to result in a modern, high performance, effective machine gun system that is a superior weapon in the field.

4. Summary • Conceiving, developing and fielding a weapon system is not an easy task. • Perhaps that is why we shy away from replacing tried and tested systems that have been used for almost the past century. • This brief presentation points out some of the advances in technology that can be applied to a new high performance machine gun system.

5. Comments on .50 Cal Heavy Machine Gun • Technology from the end of WWI (1918). • Cartridge volume is limited. No significant increase in performance. • Saboted Light Anti-Material Penetrator (SLAP) performance limited. • Overall gun-ammo system limited for performance upgrade.

6. Aerodynamicist’s Golden Rule “Assume Everything, But the Responsibility.”

7. Current and Proposed Heavy Machine Gun Systems Wt (lb) V0(ft/sec) • US 12.7mm(.50cal) 0.1014 2,800 • US 15.24mm(.60cal) • US 16.51mm(.65cal) 0.0794 5,000 • Soviet 14.5mm(.57cal) 0.1391 3,511 • US 29mm M246 0.2267 3,380

8. Characteristics of Well Designed Tubular Projectiles • High muzzle velocity +Low drag shape = High kinetic energy + short time of flight = relatively flat trajectory = high hit probability Performance bonus = high gyroscopic stability = anti-ricochet

9. Relatively New Technologies(Since Browning .50 Cal was Accepted) • Aeroballistic • Interior Ballistics • Materials (high strength & light weight) • Computer Aided Design

10. Projectiles • Tubular w/ Incendiary • Pusher/obturator • Multipurpose • Consumable • Conventional w/ HE Charge • SLAP

11. Interior Ballistics • Compacted propellant • (Proprietary designs and concepts) • Ignition Techniques • Lightweight projectile • Mass (M) + High muzzle velocity (V) = High kinetic energy (1/2MV2) • Equates to: Shorter time of flight to a given distance + some aerodynamic lift combined with low-aerodynamic drag = a relatively flat trajectory

12. Packing Density • WWII Propeller Aircraft • Jet Fighter

13. Conclusion • It is strongly recommended that the key technologies be brought together to result in a modern, high performance, effective machine gun and ammunition system that is superior to other gun-launched weapons in its general class.

14. Crimpgroove Rotatingband Boattail Lip angle Airflow Convergentarea Throat Divergentarea Full-bore Tubular Projectile Configuration 0173-04

15. Flight direction Basic Characteristics of Tubular Projectiles • Low supersonic drag • Light weight allows increased muzzle velocity • High gyroscope stability 0171-04

16. Swallowed flow No bow shock on or in front of nose Low drag Choked flow Bow shock High drag High Mach Number Low Mach Number M  1.9 Directionof flight External Flow Characteristics of Tubular Projectiles 0174-04

17. Bow shock associated with “choking” and high drag Note: Above shape is known as a Busemann Biplane andalso as an “internal” design 0172-04

18. M  3.0 M  2.5 M  2.0 M  1.6 Schlieren Photographs of TCD-3 WSCO Supersonic Wind Tunnel Variable Mach Number Operation Before high drag condition High drag condition 0176-04

19. Near muzzle 15 feet down range 20 feet down range 300 feet down range Aeroballistic Range Photographs/TCD-3 M ~ 40 0175-04

20. Tubular projectile Obturator/pusher M103 case WSC MAR 76 0183-04

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22. Potential Advantages of Tubular Projectiles • Higher launch velocity (lighter weight) • Shorter time of flight • Near straight-line trajectory profile • Simplified fire control 0170-04

23. 40 Size Weight, lb Vo, ft/sec 0.65 cal. 0.07940 5000 14.5 mm api 0.1391 3511 0.50 cal. apm2 0.1015 2800 20 mm M246 0.2267 3380 30 25 0.5 sec 20 Kinetic energy, ft-lb  103 0.5 sec 0.5 sec 15 1.0 10 1.5 1.0 1.5 0.5 sec 1.5 5 1.0 2.0 2.5 2.0 1.5 2.5 3.5 2.0 4.0 2.5 3.0 0 0 500 1000 1500 2000 Range, meters Kinetic Energy vs. Range 0182-04

24. Caliber Weight, lb T-0.65 0.0794 0.50 0.1014 5000 4000 0.5 sec 1.0 3000 Velocity, ~ft/sec 0.7 sec 1.5 1.0 2000 2.0 2.0 2.8 2.5 3.0 1000 4.0 0 0 1000 2000 3000 Range, ~meters T-0.65 Caliber vs. 0.50 Caliber 0180-04

25. .50 cal. AP:  = 2, V0 = 2800 FPS .60 cal. TCD-7:  = 0.6, V0 = 5000 FPS Vi.65 cal = 1028 FPS t = 2.60 sec and Vi.50 cal = 815 FPS t = 4.50 sec 40 Height, meters 30 20 10 Horizontal range, ~meters 0 0 500 1000 1500 2000 Representative Trajectory Profiles 0181-04

26. Summary of .65 Caliber Tubular Projectile Characteristics • Significant increase in kinetic energy over .50 caliber • Terminal ballistics far superior to .50 caliber AP • Flatter trajectory than .50 caliber • Shorter time of flight than .50 caliber • Greater range than .50 caliber • Low weight system/low cost ammunition DRDAR-ACW 0169-04

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28. “That’s how Research and Development put the pressure on. First they hustle you to promise them results. Then they hustle you some more to promise them results in our lifetime!” 0177-04