1. Adaptive Muzzle Brakes (AMB’s)
Managing and Mitigating Firearm Recoil Through the Development of Novel New Designs of Muzzle Brake
Talk about how this is all my own research and the work was done for my university dissertation (this was a topic of my own invention)

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?
My name is Tim Clark, I’m a year in industry student here in air division.
I’ve completed 3 years at the university of Southampton studying aeronautical engineering with a specialism in aerodynamics.
I’ll be returning to university next year, for a year, to complete my masters degree.
What I’m about to talk about is the research I undertook as part of my 3rd year dissertation.
This centred around utilising Computational Fluid Dynamics (CFD) to test a novel new design of muzzle brake.
Firstly I’m going to explain my reasoning behind this project and why I believe there is potentially a large market for new methods of managing recoil from firearms.
Then I will briefly discuss my research so far.
And finally where I hope to take this research in the future.

3. Body Armour Development
[1]
[2]
Shown here are two US Body Armour Systems that saw wide spread deployment.
On the left a PASGT vest from the 1980’s
(Personnel Armour System for Ground Troops)
On the right an IBA vest that was introduced in the early 2000’s
(Interceptor Body Armour)
Talk about how body armour has rapidly spiked in effectiveness over the last 30 years,
In the 1980’s US body armour was barely able to stop a low speed pistol round
Now modern ceramic plate armour is capable of stopping all widely used ammunition types
Whilst currently this technology is expensive and somewhat unwieldy the current rate of development is unlikely to abate
And with further progress will come falling prices and proliferation of this technology
1980’s
2000’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.
Relatively self explantory,

5. Firearm Development
This slide will talk about how recoil is linked to muzzle velocity and how muzzle velocities have barely changed over the last 60 years.
The Nato Standard round has been in place for several decades now.
With the ever improving capability of body armour this will have to change and a new higher energy round will need to be introduced.
Body Armour Technology will grow cheaper and the technology will proliferate and the need for a more effective round will be needed.
This will result in the wide spread usage of weapons with very high recoil levels
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”.
Talk about medical issues associated with high recoil weaponry
How the development of new more powerful rounds is going to open up a huge new market for recoil mitigation systems.

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

8. Recoil Mitigation 1) Mechanical Systems:
Springs and Dampers mounted in the Rifle Stock
Talk about how springs and dampers can be used in the stock of the weapon, similar to the floating barrel
[5]

9. Recoil Mitigation 2) Aerodynamic Systems: Muzzle Brakes [6] [7]
Talk about how muzzle brakes work
Redirected propellant gas to produce a counter recoil force
This is the only recoil mitigation method that actually reduces recoil, mechanical systems just spread the recoil force over a larger time which results in a feeling of lessened recoil but no actual reduction.
[7]

10. Muzzle Brake Geometry Historic Current [8] [9] [10] [11]
Talk about how Muzzle Brake geometry has barely changed over the last 60 years
I believe this is
[10]
[11]

11. Muzzle Brake Geometry
Historic
Current
[12]
[13]
Muzzle brake designs have remained strikingly similar to the designs used in World War 2.
This slide will talk about how recoil is linked to muzzle velocity and how muzzle velocities have barely changed over the last 60 years.
The Nato Standard round has been in place for x number of years now.

12. The Muzzle Brake Trade-off
Need to talk about how highly efficient muzzle brakes direct the blast wave backwards which can damage the crew/users and how therefore muzzle brakes are a compromise between efficiency and crew SPL
How this trade off is intrinsic to current muzzle brake designs
These Images show the broadly spherical travel of the blast wave, how it is travelling roughly equally from the blast.

13. The Muzzle Brake Trade-off
Compare and contrast this slide to the previous slides images,
This muzzle brake (a flat plate positioned 1 calibre away from the muzzle exit with a width of 2.5 calibres)
Radically changes the shape of the initial blast wave, becomes far more torodal in nature
Much Stronger show wave can be seen travelling backwards towards the user.
This is a relativelty ineffective muzzle brake but it neatly illustrates the fundamental trade-off at the heart of current muzzle brakes,
the more efective your muzzle brake design the stronger the backwards travelling shockwaves will be.

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.
My dissertation focused on the feasibility and computation testing of an AMB and was the first public work on the subject.
Shown above is a prototype design produced for my dissertation that is designed to fit onto an M14 rifle.
Explain the thinking behind the design:
Talk about analysis method in this slide, the use of CFD and stuff
Allows for a highly compact muzzle brake
But hopefully highly efficienct when it opens as the flow sees a similar shape to known highly effective muzzle brakes of today.
Upon firing the muzzle brake flaps flare open.
The idea would be to have springed hinges that hold the flaps closed
That are then forced open upon firing
Muzzle brakes of this sort of design, with moving geometry, have never been tested before (to the best of my knowledge)

15. Muzzle Brake Designs Tested
Perforated Circular
Shock Reflection
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.
Compare and contrast the two images, focus on the toroidal nature of both images and the distinct peaks and troughs in the images
[14]

18. CFD Results – AMB Closed
Talk about how the AMB has a much smaller shockwave travelling backwards as opposed to the more traditional muzzle brake designs shown above
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.
Talk about how the AMB in its open position exhbibits very similar performance to a high angle arrowhead muzzle brake
A muzzle brake that is known to be very effective and in wide scale usage currently

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
Talk about how the AMB in its open position exhbibits very similar performance to a high angle arrowhead muzzle brake
A muzzle brake that is known to be very effective and in wide scale usage currently

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).
Talk about how I will be continuing my research (thanks to funding from QinetiQ) next year with a group of students
I will be aiming to produce a design that work axially and actually seals off the hole the bullet moves through.
This will allow for a dramatic increase in efficiency
Alexandar Davies, KC Phan

22. Any Questions?
Talk about how I will be continuing my research (thanks to funding from QinetiQ) next year with a group of students
I will be aiming to produce a design that work axially and actually seals off the hole the bullet moves through.
This will allow for a dramatic increase in efficiency
Alexandar Davies, KC Phan

23. Bibliography
[1] : PASGT Vest Image, Flatwood Museum,
[2]: IBA body armour, wikimedia,
[3]: H&K G11 Cutaway,
[4]: H&K G11 Barrel Assembly,
[5]: Recoil Mitigating Stock,
[6]: Muzzle brake High Speed Photography:
[7]: Marines in Fallujah,
[8]: M1A Rifle Muzzle Brake, Police Mag,
[9] : .25 cal. Muzzle Brake, Amazon,
[10]: Boys Anti-Tank Rifle Muzzle Brake, Rifleman,
[11]: Grizzly Gunworks Muzzle Brake,
[12] : Panther Tank Muzzle Brake,
[13]: 30mm Mauser Cannon Muzzle Brake,
[14]: .308 Rifle High Speed Photography,