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Adaptive Muzzle Brakes (AMB’s). Managing and Mitigating Firearm Recoil Through the Development of Novel New Designs of Muzzle Brake. Introduction. Project completed as 3 rd year dissertation. Proof of concept study using CFD of a novel new muzzle brake design. Contents:
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Adaptive Muzzle Brakes (AMB’s) Managing and Mitigating Firearm Recoil Through the Development of Novel New Designs of Muzzle Brake
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?
Body Armour Development [1] [2] 2000’s 1980’s
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.
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.
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”.
Recoil Mitigation • Two Methods of Mitigating Recoil: • 1) Mechanical Systems: • Floating Barrel (as found in the H&K G11 Advanced Rifle Prototype) [3] [4]
Recoil Mitigation • 1) Mechanical Systems: • Springs and Dampers mounted in the Rifle Stock [5]
Recoil Mitigation • 2) Aerodynamic Systems: • Muzzle Brakes [6] [7]
Muzzle Brake Geometry Current Historic [8] [9] [10] [11]
Muzzle Brake Geometry Current Historic [12] [13] • Muzzle brake designs have remained strikingly similar to the designs used in World War 2.
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.
Muzzle Brake Designs Tested Shock Reflection Perforated Circular High Angle Arrowhead Static AMB Geometry
CFD Results – No Muzzle Brake • Velocity contours over a period of 4 millionths of a second. • Contours range from 0 to 1400 ms-1.
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]
CFD Results – AMB Closed • Total pressure contours. • Contours range from 0 to 50 atmospheres of pressure.
CFD Results – AMB Open • Total pressure contours. • Contours range from 0 to 50 atmospheres of pressure.
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
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).
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