Adaptive Muzzle Brakes (AMB’s)

1. Adaptive Muzzle Brakes (AMB’s) Managing and Mitigating Firearm Recoil Through the Development of Novel New Designs of Muzzle Brake

2. Introduction • Project completed as 3rd year dissertation. • Proof of concept study using CFD of a novel new muzzle brake design. • Contents: • Background information and reasoning • My research so far • What next?

3. Body Armour Development [1] [2] 2000’s 1980’s

4. Methods for Defeating Armour • Increased projectile mass or speed • Both are increasing projectile energy. • Both will result in increased recoil. • Projectile shaping and material • Highly effective and can be applied to existing calibres. • Expensive to produce.

5. Firearm Development • Bullet calibres in small arms have remained the same for nearly half a century and muzzle velocities have only slightly increased. • Therefore projectile energies in small arms have remained roughly constant. • Due to the improvements in body armour there are indications larger calibre rounds may be required in the future.

6. The Problems of Recoil • 20 J of free recoil energy is commonly cited as the point where recoil becomes uncomfortable for the user. • A study carried out by US Army Research Institute of Environmental Medicine in 2004 showed that: • 93% of soldiers experienced bruising to the shoulder after firing only 15 rounds with a high recoil rifle. • Soldiers firing weapons with high recoil would quickly develop a “reluctance to fire”.

7. Recoil Mitigation • Two Methods of Mitigating Recoil: • 1) Mechanical Systems: • Floating Barrel (as found in the H&K G11 Advanced Rifle Prototype) [3] [4]

8. Recoil Mitigation • 1) Mechanical Systems: • Springs and Dampers mounted in the Rifle Stock [5]

9. Recoil Mitigation • 2) Aerodynamic Systems: • Muzzle Brakes [6] [7]

10. Muzzle Brake Geometry Current Historic [8] [9] [10] [11]

11. Muzzle Brake Geometry Current Historic [12] [13] • Muzzle brake designs have remained strikingly similar to the designs used in World War 2.

12. The Muzzle Brake Trade-off

13. The Muzzle Brake Trade-off

14. Adaptive Muzzle Brakes (AMB’s) Pre-firing Post-firing • Adaptive muzzle brakes are muzzle brakes that feature geometry capable of moving in response to firing. • AMB’s could potentially solve the problem of the muzzle brake trade off. • They could also allow for dramatic increases in efficiencies over current muzzle brake designs.

15. Muzzle Brake Designs Tested Shock Reflection Perforated Circular High Angle Arrowhead Static AMB Geometry

16. CFD Results – No Muzzle Brake • Velocity contours over a period of 4 millionths of a second. • Contours range from 0 to 1400 ms-1.

17. CFD Results – No Muzzle Brake • Total pressure contours over a period of 10 millionths of a second. • Contours range from 0 to 50 atmospheres of pressure. [14]

18. CFD Results – AMB Closed • Total pressure contours. • Contours range from 0 to 50 atmospheres of pressure.

19. CFD Results – AMB Open • Total pressure contours. • Contours range from 0 to 50 atmospheres of pressure.

20. Summary • This research has shown that: • AMB’s can significantly reduce the recoil of a firearm. • AMB’s do not increase the sound pressure levels for the user upon firing. • Due to this AMB’s eliminate the problems traditional muzzle brakes face. • The use of AMB’s could allow for a dramatic increase in the lethality of small arms through the use of higher energy rounds with no detrimental effects on the user. • AMB’s could also be applied to large calibre weapons and moving platforms such as: • Tanks • Aircraft • Naval Guns • Artillery

21. What Next? • Looking to continue the development of AMB’s into my 4th year group design project. • Pitched this idea to weapons division who have provisionally agreed to fund my research. • The final aims of the project would be to produce a far more refined AMB design that will pioneer: • Utilising axially moving components to allow for dramatically increased durability. • A mechanism that will seal the hole the projectile passes through after it has left the muzzle brake which could allow muzzle brake efficiencies of 70-80% to be achieved (as opposed to the 30-40% efficiencies of current designs).

22. Any Questions?

23. Bibliography [1] : PASGT Vest Image, Flatwood Museum, http://www.flatwoodsmuseum.com/uploads/2/3/4/8/23482946/422880_orig.jpg [2]: IBA body armour, wikimedia, https://upload.wikimedia.org/wikipedia/commons/5/54/MultiCam_IBA.jpg [3]: H&K G11 Cutaway, http://weapon-planet.ru/images/gallery/HK_G11/HK_G11_01.jpg [4]: H&K G11 Barrel Assembly, http://www.fadych.com/wp-content/uploads/2015/03/media4051.jpg [5]: Recoil Mitigating Stock, https://www.gunsamerica.com/UserImages/1881/930353445/wm_3311197.jpg [6]: Muzzle brake High Speed Photography: http://kuulapaa.com/onewebstatic/4d0e0dc4b7-Comptest-FerfransCQB-SivuA4_2_FIN_Single_1500.jpg [7]: Marines in Fallujah, https://upload.wikimedia.org/wikipedia/commons/f/f7/4-14_Marines_in_Fallujah.jpg [8]: M1A Rifle Muzzle Brake, Police Mag, http://www.policemag.com/channel/weapons/articles/2002/01/arsenal.aspx [9] : .25 cal. Muzzle Brake, Amazon, http://www.amazon.com/17-HMR-Cal-Muzzle-Brake/dp/B00GRDE03M [10]: Boys Anti-Tank Rifle Muzzle Brake, Rifleman, http://www.rifleman.org.uk/Enfield_Boys_Anti-Tank_Rifle.htm [11]: Grizzly Gunworks Muzzle Brake, http://www.thetruthaboutguns.com/2014/04/joe-grine/gear-review-grizzly-gunworks-ltd-muzzle-brakes/ [12] : Panther Tank Muzzle Brake, http://www.network54.com/Forum/47207/thread/1195602367/Panther+muzzle+detail [13]: 30mm Mauser Cannon Muzzle Brake, https://en.wikipedia.org/wiki/Muzzle_brake [14]: .308 Rifle High Speed Photography, http://kuulapaa.com/home/highspeedx.html