Home Forums Hunting & Shooting Ask The Gunwriters Help me understand why muzzle brakes reduce recoi.

I just don't get how a muzzle brake reduces a rifles recoil.

You drill holes in the tip of the barrel and recoil is reduced. Does this mean that recoil continues to be reduced as you increase the number of holes ? This does not make sense as you could drill holes untill the tip of the barrel is all holes and the recoil would be the same as before you started drilling holes holes. I have to be missing something. <img src="/ubbthreads/images/graemlins/confused.gif" alt="" />

Conrad

The operating theory is that the holes in the brake divert some of the exiting powder gas toward the rear, which reduces the forward jet thrust of the gas and even exerts a forward push on the muzzle.

Some work.

Some don't.

In fact, some brakes actually increase the effective recoil by reducing the rise of the muzzle so that all the exiting gas pushes the rifle straight back.

Many degrade accuracy. In one extensive test years ago, every brake tested made the barrel shoot larger groups.

Most make the muzzle blast louder.

Does that mean that the recoil is determined by the last 3-4 inches of the barrel ?

If I keep increasing the number of holes the recoil reduction is increased as more of the exhaust is diverted ?

What happens when the tip of the barrel disappears because it is all holes ?

Do shorter barrels (ie 22" verses 26") have significantly (40-60%) less recoil ?

Many brakes have holes that are drilled at an angle such that escaping gas is directed backwards. The effect is like a jet engine. High pressure gas exiting in a rearward direction provides a corresponding thrust forward which alleviates some of the recoil forces directed back towards the shooters' shoulder. Due to the speed of the exhausting gases, I believe only a limited amount is able to enter the holes, if you add more holes, eventually you will come up with diminishing returns and there will be no more reduction in recoil. If you had more holes than metal, I believe the recoil reduction would be the same as a smaller number. If you cut the entire section off, you revert back to unported recoil because now there are no more gases pushing the gun forward. A shorter barrel will recoil more due to the loss of weight but unless your are talking very extreme changes in weight like a 28" cut back to 20" I doubt you'd be able to feel the difference. These are all just my opinions based on my experiences and I'll not take offence if someone else knows more or finds error with what I've written.

NoCAL

It's really simple. A brake makes the rifle so dam loud that the ringing in your ears makes you forget that the mule of a magnum rifle just kicked the [bleep] out of your shoulder. <img src="/ubbthreads/images/graemlins/wink.gif" alt="" />

PDS,
Agreed. They are obnoxious.

Conrad,

There are two components that create recoil: the acceleration of the bullet, and the acceleration of powder/gas (the powder creates the gas as it burns).

The recoil caused by the bullet being accelerated down the bore cannot be eliminated so lets look at the acceleration of the gases.

As the powder burns, the gas forces the bullet to the end of the barrel. The mass of the powder has turned into a gas and has expanded or accelerated down the barrel and is pushing on the base of the bullet. This part of the acceleration of the gas cannot be eliminated.....it's required to push the bullet down the barrel.

Now the part that can be reduced. When the bullet exits the bore, the gas (which has been under significant pressure) now has an opening to escape. The gas then accelerates down the barrel to exit the muzzle. The exit velocity of the gas can be quite high. If the mass of the gas is roughly equal to the mass of the powder and it is accelerated to speeds greater than the bullet, then it produces a significant amout of recoil. If the gases are accelerating forward (down the barrel) recoil is in the opposite direction (toward your shoulder).

What if you changed the direction some of the gas was venting? Wouldn't the redirected gas accelerate in the new direction and that gas would no longer be pushing against your shoulder? If you change the direcion of the exiting gas where it angles back slightly toward the shooter, not only will the redirected gas not push against the shooters shoulder but will actually work to push the rifle away from the shooters shoulder thus cancelling some of the effect of gas that does accelerate out the end of the muzzle.

That is how a muzzle break works.....by changing the direction that some of the gas is accelerated it pushes (recoils) in a new direction. If you vent gas out opposite sides of a muzzle break the recoil from each side cancels the other out (and neither is pushing toward the shooters shoulder).

If you redirect some of that high pressure gas in the direction of the shooter, imagine what a pressure wave hits the shooters eardrum.

HogWild

Hogwild,
Good explanation...... it's not really all that complicated. In defense of brakes I must say that they make range work much more enjoyable as long as you wear proper hearing protection. I made the mistake of shooting a rifle equiped with a brake without protection one time and that was plenty <img src="/ubbthreads/images/graemlins/crazy.gif" alt="" />. I would'nt own a rifle with a brake that couldn't be unscrewed unless it was strictly for target and varmint hunting.

Jeff

Thank you Sir. I understand now.