Just wondering if anyone has any documentation on the science and math behind muzzle break design. I know there is a lot of trial and error in designing an effective muzzle break, but are there any hard fast rules that must be followed?
What is the science and math behind muzzle break design?
- Thread starter Allen Gun Works
- Start date
I have been doing a little research on different designs, the ones I have seen seem to alternate the port angles, straight out and angled forward. Also I have read about making sure the gas expands evenly as the bullet leaves the muzzle to control the tipping effect
I have made up, and installed about 40 muzzle brakes over the last couple of years (on target and hunting rifles) and I can honestly tell you, that there is very little science and math behind muzzle break design.
A piece of steel screwed on the end of the barrel with a large hole drilled from side to side (like the one you see in on a tank) is just as effective as any fancy design you see advertised with ridiculous claims.
35 to 40 % of reduction is all you are going to get, and nothing more.
The ones I made up are about 2" long with an expansion chamber the length of the large diameter of the bullet, four rows of 3/16" dia holes, and the exit hole is about .020" over bullet size.
The brakes for a .50 BMG may have some additional benefits by drilling the holes on a backward angle, but you don’t want a large odd shaped block of steel on your hunting, or target rifle.
A piece of steel screwed on the end of the barrel with a large hole drilled from side to side (like the one you see in on a tank) is just as effective as any fancy design you see advertised with ridiculous claims.
35 to 40 % of reduction is all you are going to get, and nothing more.
The ones I made up are about 2" long with an expansion chamber the length of the large diameter of the bullet, four rows of 3/16" dia holes, and the exit hole is about .020" over bullet size.
The brakes for a .50 BMG may have some additional benefits by drilling the holes on a backward angle, but you don’t want a large odd shaped block of steel on your hunting, or target rifle.
Thane O'Dell
Member
- Location
- 15 min. west of London ON.
I made 2 for a .243 win. The first one did not work, I believe it did not have enough holes to release the gases before the bullet exited.
The second one I made was a 2 piece rig with larger holes and the end cap having a cone nose inside to encourage the gases to flow outwards while the bullet was blocking the exit hole which was .010 larger then the bullet. this one works well. I agree with Al with regards of the percentage of recoil reduction.
Thane
The second one I made was a 2 piece rig with larger holes and the end cap having a cone nose inside to encourage the gases to flow outwards while the bullet was blocking the exit hole which was .010 larger then the bullet. this one works well. I agree with Al with regards of the percentage of recoil reduction.
Thane
Here's the math. x=holes in barrel y= $CDN. e=gullible buyer
or 12(holes in barrel) X $10(per hole)=$120+e(1 gullible buyer)
Now the science: for every action there is an opposite reaction, increased muzzle blast, increased length of barrel=e(see gullible buyer above)
or 12(holes in barrel) X $10(per hole)=$120+e(1 gullible buyer)
Now the science: for every action there is an opposite reaction, increased muzzle blast, increased length of barrel=e(see gullible buyer above)
Mystic Precision
CGN Ultra frequent flyer
- Location
- Summerland, BC
Empirically, the bigger and wider a muzzle brake is, the better. The larger the area for the exit ports the better. The higher the number of chambers, the better. KDF style brake equals one chamber. AR50 brake has two. Gill style brakes can have more.
Directing 90deg and more backwards vs the direction of the bullet, the better. So the higher the concussion wave moving in another direction from bullet travel, the better - "noisy" brakes work better then 'quiet' ones.
Exit bore should not exceed 20thou over bullet diameter. However, you must have at least 5 thou clearance or there will be issues with hitting the brake and turbulence.
From there, let your imagination and application be your guide. And yes, given the same exterior dimensions and exit port sizes, these brakes will work pretty much the same no matter what their manf may claim. These brakes are going to reduce recoil 35 to 50%.
A rearward facing large gill brake might raise that up to around 60% given the port pressures and gas volume of the cartridge fired.
The more overbore the cartridge given a barrel length, the more effective that brake will seem. Example - 308 fired in a braked barrel will have a 'higher preceived' recoil, then a 300WSM shooting the same weight bullet at much higher velocity (magnum pressures). The much higher port pressures and gas volume makes the brake work better.
Jerry
Directing 90deg and more backwards vs the direction of the bullet, the better. So the higher the concussion wave moving in another direction from bullet travel, the better - "noisy" brakes work better then 'quiet' ones.
Exit bore should not exceed 20thou over bullet diameter. However, you must have at least 5 thou clearance or there will be issues with hitting the brake and turbulence.
From there, let your imagination and application be your guide. And yes, given the same exterior dimensions and exit port sizes, these brakes will work pretty much the same no matter what their manf may claim. These brakes are going to reduce recoil 35 to 50%.
A rearward facing large gill brake might raise that up to around 60% given the port pressures and gas volume of the cartridge fired.
The more overbore the cartridge given a barrel length, the more effective that brake will seem. Example - 308 fired in a braked barrel will have a 'higher preceived' recoil, then a 300WSM shooting the same weight bullet at much higher velocity (magnum pressures). The much higher port pressures and gas volume makes the brake work better.
Jerry
Turret Monster
CGN Regular
- Location
- New Brunswick
Al Flipo said:
There is a whole lot of math and science involved. But like anything, you can trial-and-error it until you get something that works. But math and science will make it better.
First of all, think of why a muzzle brake works. Similar to a compressed gas cylinder that becomes a torpedo (Mythbusters comes to mind), or the recoil felt from a fire hose when the first blast of water shoots out. A jet of fluid (gas or liquid) leaving a body exhibits a force in the opposite direction.
At the muzzle, the propellant gas is done its job of accelerating the bullet, and now provides the negative side effect of causing recoil. So a hole drilled into the side will shoot gasses out at 90 degrees. Since that means less gas is leaving straight forward, it will reduce recoil. If the gas is perfectly distributed, and the gas ports are perfectly located, then the force acting left and right on the muzzle will cancel each other out. So the better your machine, machinist, tool bits, and measuring equipment, the closer to perfect it will be. Poor workmanship will actually cause your muzzle to jump left or right, though these effects may be negligeable for say a hunter shooting a dear at 100m, it may be critical to a marksman shooting a gong at 800m, etc.
Now if that gas is ported backwards, it reduces recoil by reducing the amount of gas leaving forward, but also by providing a force in the opposite direction, further reducing recoil.
Knowing that recoil isn't completely eliminated, and knowing that a rifle/muzzle will 'jump' upward due to the hold of the rifle, some muzzle brakes have ports on top to provide some downward thrust to help reduce jump.
IIRC, the force caused by the jet of gas is related to Density of the gas, Area of the exit port NORMAL to the flow of gas, and the Velocity of the gas. This accounts for the size and directions of the ports. The direction of flow determines how much of this force is used against the recoil.
The gas will lose velocity while being redirected rearward, but proper design can limit losses. Surface roughness, turn radius, and shape/geometry all affect the flow velocity.
To further improve designs, the fluid flow needs to be modeled. This will require expensive software which is better left to the larger manufaturers.
So a simple design like AlFlipo mentioned may be suitable for a lot of people, both with respect to performance and cost. A calculated and well thought-out design could be made by someone with some Fluid Mechanic and Manufacturing/Machining background. And the best design would be made by an engineering team and computer software and C&C machinery. Though I suspect that many of the fancy-a$$ muzzle breaks on the market have you paying for looks, I have no doubt that some are well designed pieces.
I assume you were looking for info on the middle ground - so your next step would be to pick up a text book from a fluid mechanics course at a college or university. I have 'Fluid Mechanics 5ed by Frank M. White' and 'Fundamentals of Fluid Mechanics 5ed by Munson, Young, and Okiishi'. Either one will give you what you need.
TM
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