Thread: Suppressors - Am I missing something

Originally Posted by gundoc

True, the efffect is lost to some extent (but far from completely) if the brake is enclosed, which is why over-barrel suppressors have the tube behind the brake to give the gases somewhere to go and expand.

Yes as the gas comes back it hits the suppressor pushing it back negating its recoil reducing effect.

This one is inside a magnum suppressor & has about 125mm behind it.

Originally Posted by gundoc

4 bloody pages of theoretical bumph! The question was about internal muzzle brakes in suppressors. The answer is that all suppressors have a recoil reducing effect by virtue of their baffles providing an impingment surface to the muzzle gases, tending to put forward pressure in the suppresor. .......

....There has been more psuedo-scientific garbage written (and claimed) about suppressors than you can shake a stick at. I have commercially designed and manufactured thousands of suppressors for all types of firearms since the early 1970's. Suppressors rely on only three factors for efficient operation; accurate alignment with the bore, an efficient (but simple) baffle design, and sufficient internal volume to contain most of the muzzle gases. Any claims outside of these parameters are dubious at best!

@gundoc,

With all respect for your conclusion which I can only agree with, you are harsh on other contributors, even arrogant... and in karmic fashion immediately plunge neck-deep into the bog of your version of Munchausen's pigtail self-lift.

To paraphrase your first bit, when a car passenger kicks the dashboard the car pulls forward. We all know this is false. The explanation is that the passenger supports his back against his seat, so the effect of his forward blow against the dashboard is entirely cancelled by his rearward action against his seat as both objects are fixed to the car. It must be understood that the gun and silencer are attached to each other. They are a single unit; the silencer is part of the gun. A blow from a gun against itself (in the form of impingement of its gases against its own baffles) will not pull it forwards.

Astronauts on a spacewalk similarly can not propel themselves through space by slapping their own butts.

Originally Posted by Cordite

@gundoc,

With all respect for your conclusion which I can only agree with, you are harsh on other contributors, even arrogant... and in karmic fashion immediately plunge neck-deep into the bog of your version of Munchausen's pigtail self-lift.

To paraphrase your first bit, when a car passenger kicks the dashboard the car pulls forward. We all know this is false. The explanation is that the passenger supports his back against his seat, so the effect of his forward blow against the dashboard is entirely cancelled by his rearward action against his seat as both objects are fixed to the car. It must be understood that the gun and silencer are attached to each other. They are a single unit; the silencer is part of the gun. A blow from a gun against itself (in the form of impingement of its gases against its own baffles) will not pull it forwards.

Astronauts on a spacewalk similarly can not propel themselves through space by slapping their own butts.

Attachment 76413

100% correct. As stated it is a closed system.

You must look at it from an external point of view in order to make sense as I stated earlier. The reduction in recoil from a suppressor can only come from the reduced gas emission speed from the muzzle (which is now the end of the suppressor) and the extra mass added to the system. It is only when something leaves the system (the projectile and gases leave the muzzle) that the conservation of momentum is applied. This will give the initial speed and hence energy of the recoil. @gundoc, this is simple high school physics.

Originally Posted by Cordite

@gundoc,



To paraphrase your first bit, when a car passenger kicks the dashboard the car pulls forward. We all know this is false. The explanation is that the passenger supports his back against his seat, so the effect of his forward blow against the dashboard is entirely cancelled by his rearward action against his seat as both objects are fixed to the car. It must be understood that the gun and silencer are attached to each other. They are a single unit; the silencer is part of the gun. A blow from a gun against itself (in the form of impingement of its gases against its own baffles) will not pull it forwards.


Attachment 76413

Two points, 1) there is an effect with the energy transfer in your example- the seat resists the rearwards force at the same rate with that the dashboard resists the forwards force. A better example the person bouncing between the seat and the dashboard hitting them at different times thus producing a rocking motion. Yes the silencer and gun are attached but the gas that hits the brake portion and are forced rearwards are given moments to cool and slow thus the speed with which they hit the rear of the suppressor tube is reduced. If a gas hits the front with a high speed and is forced rearwards within the can then hits the rear of the can with a reduced speed due to the cooling and turbulence encountered, then both ends are not subjected to equal countering forces.

And as a final note, the air thrust forward in your cartoon has been shown to actually work. Poorly but with some gain in forward momentum. Mainly due to the same aerodynamic principle that means an anemometer works. The dome shape at the front resists the air less than the shape behind it.

Originally Posted by timattalon

And as a final note, the air thrust forward in your cartoon has been shown to actually work. Poorly but with some gain in forward momentum. Mainly due to the same aerodynamic principle that means an anemometer works. The dome shape at the front resists the air less than the shape behind it.

@timattalon,
Yes, blowing into a large sail with a big fan actually can produce a forward drive. I saw that Mythbusters episode, and it was really good they bothered to test it as the result was forward motion of the craft!!! The reason for this apparent miracle is that the sail deflected the blast of the fan sideways and rearwards. I.e. it nevertheless still illustrates an open system, not an enclosed system like a muzzle brake enclosed in a can and unable to ultimately direct blast in other directions than forwards.

Originally Posted by Cordite

@gundoc,

With all respect for your conclusion which I can only agree with, you are harsh on other contributors, even arrogant... and in karmic fashion immediately plunge neck-deep into the bog of your version of Munchausen's pigtail self-lift.

To paraphrase your first bit, when a car passenger kicks the dashboard the car pulls forward. We all know this is false. The explanation is that the passenger supports his back against his seat, so the effect of his forward blow against the dashboard is entirely cancelled by his rearward action against his seat as both objects are fixed to the car. It must be understood that the gun and silencer are attached to each other. They are a single unit; the silencer is part of the gun. A blow from a gun against itself (in the form of impingement of its gases against its own baffles) will not pull it forwards.

Astronauts on a spacewalk similarly can not propel themselves through space by slapping their own butts.

Attachment 76413

I am well aware that you cannot stand in a bucket and pick it up by the handle, however my comments are backed up by years of experimentation and manufacture (probably more than any current manufacturer). Suppressors are not a 'closed system' and, despite the efficiency of any baffle system, a decent percentage of the gases exit the muzzle in front of, and behind, the bullet. I guess I will just have to set up an experimental pendulum (friction free as opposed to a slide) and publish the results of the recoil dampening effect of various suppressors and muzzle brakes.

I don't intend to be harsh on individual opinions but I have heard too much garbage and pseudo-scientific rambling on the subject of suppressors over the years, and it irritates me!

I have a JP AR15 and recently bought an NEA carbine off a forum member with a Gunworks Maximus suppressor fitted.

The JP is a heavy rifle with an 18" heavy contour barrel and I have an overbarrel suppressor that fits back to the gas block and in turn has a smaller diameter to fit thru the JP handgaurd.

It is a few inches longer than the maximus.
And about 1/2-3/4 the diameter.

The NEA, surprisingly is noticeably quieter (with a shorter barrel) and seems to settle back faster than the JP when shooting fast or double tapping Ipsc targets.

Just a quick observation with no tech data to back it up but it to me it seems that internals and size of a suppressor can make a difference.
Both suppressors have integral breaks and same stock fitted.

Without the suppressor and with the JP break fitted the JP shoots quicker again.


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Put more briefly, A muzzle brake by itself actively provides a physical forwards push to counteract the recoil. But my understanding of a suppressor is that rather that reduce the amount of energy, is slows the energy transfer to take longer reducing the time that the impact takes place. Same amount of energy transferred (or very similar) but by taking longer the speed / force of the impact is reduced.
To use the car analogy, think of a muzzle brake as an anchor attached to a chain thrown out the back that grabs the ground and applies a pull to the rear that slows the car. Where a suppressor is the act of apply a foot brake that is part of the car. (Not quite the same but I think close enough to get my point.

For all those that are telling us that suppressors cannot reduce recoil forces, please explain why most shooters find suppressed rifles are more pleasant to shoot with what certainly feels like significantly reduced recoil.......

My 7.62x54R boots like a bastard without a suppressor and leaves bruises on my (slightly built) hunting mate after a few shots, (and has flames you can almost spotlight with) but add a suppressor and he can put a couple packets through with no problems or bruising. (And I know this to be true as I have seen it and experienced the difference myself.) If suppressors do not have any effect on recoil, please explain this for us as this is very close to what the OP asked.

Originally Posted by timattalon

Put more briefly, A muzzle brake by itself actively provides a physical forwards push to counteract the recoil. But my understanding of a suppressor is that rather that reduce the amount of energy, is slows the energy transfer to take longer reducing the time that the impact takes place. Same amount of energy transferred (or very similar) but by taking longer the speed / force of the impact is reduced.
To use the car analogy, think of a muzzle brake as an anchor attached to a chain thrown out the back that grabs the ground and applies a pull to the rear that slows the car. Where a suppressor is the act of apply a foot brake that is part of the car. (Not quite the same but I think close enough to get my point.

For all those that are telling us that suppressors cannot reduce recoil forces, please explain why most shooters find suppressed rifles are more pleasant to shoot with what certainly feels like significantly reduced recoil.......

My 7.62x54R boots like a bastard without a suppressor and leaves bruises on my (slightly built) hunting mate after a few shots, (and has flames you can almost spotlight with) but add a suppressor and he can put a couple packets through with no problems or bruising. (And I know this to be true as I have seen it and experienced the difference myself.) If suppressors do not have any effect on recoil, please explain this for us as this is very close to what the OP asked.

@timattalon,

I do not hear many say suppressors do not reduce recoil (which by definition have to mean felt recoil). The cooling and thus contraction of muzzle gases with resultant loss of pressure will reduce recoil. The slower release of gases will reduce felt recoil, just like it is more comfortable to accelerate to 100km from standstill over 15 seconds rather than 5 seconds! But the final energy of the car is the same.

As for your little friend and your gun, if he is a seasoned shooter and has that problem, I take it he is shooting prone?

Shooting Big Guns 101. Shoot a full power battle rifle without having it firmly against your shoulder. It will fly backwards at the speed of a fast marching pace. When it thus contacts you (rams you), you will hurt, likely bruise, no matter your body size. Thus people who shoot for the first time may be put off the sport as their fears of recoil are doubly confirmed when they hold the butt too lightly against their shoulder.

A slight lady shooting standing or kneeling with her rifle pressed firmly to her shoulder will absorb the recoil into her shoulder, and her torso will give and twist, with minimal or no hurt therefore to the shoulder. No such luck if she shoots prone.

Someone like myself shooting the same rifle in the standing position will just have a bit more local shoulder hurt to contend with, as my body is simply too big to recoil back as much as hers. My rifle butt will instead dig in more locally into my shoulder region. If I change to the prone shooting position I don't really notice much extra recoil therefore, but the wee girl will experience a relatively larger increase in recoil on shooting prone.

Just watch youtube funny videos of "I lent my wee girlfriend my big manly gun" and you usually see failure to make firm shoulder contact. All it says is, "her boyfriend is an idiot and will he never get a girlfriend who enjoys shooting with him".

Your wee friend should maybe shoot standing or kneeling, with a firm shoulder contact, even though he may feel safer handling a big gun lying prone. But things are not what they seem.

Of course, especially in shooting positions that allow your body to recoil back with the gun, having a gradual power release from the suppressed gun will allow your body to absorb the recoil more widely and move back with the gun. On an accuracy point, the suppressor allows you to hold the gun less firmly against your body, and thus less heartbeat oscillation is transmitted to it.

Hope this is helpful.

Originally Posted by Cordite

@timattalon,

I do not hear many say suppressors do not reduce recoil (which by definition have to mean felt recoil). The cooling and thus contraction of muzzle gases with resultant loss of pressure will reduce recoil. The slower release of gases will reduce felt recoil, just like it is more comfortable to accelerate to 100km from standstill over 15 seconds rather than 5 seconds! But the final energy of the car is the same.

As for your little friend and your gun, if he is a seasoned shooter and has that problem, I take it he is shooting prone?

Shooting Big Guns 101. Shoot a full power battle rifle without having it firmly against your shoulder. It will fly backwards at the speed of a fast marching pace. When it thus contacts you (rams you), you will hurt, likely bruise, no matter your body size. Thus people who shoot for the first time may be put off the sport as their fears of recoil are doubly confirmed when they hold the butt too lightly against their shoulder.

A slight lady shooting standing or kneeling with her rifle pressed firmly to her shoulder will absorb the recoil into her shoulder, and her torso will give and twist, with minimal or no hurt therefore to the shoulder. No such luck if she shoots prone.

Someone like myself shooting the same rifle in the standing position will just have a bit more local shoulder hurt to contend with, as my body is simply too big to recoil back as much as hers. My rifle butt will instead dig in more locally into my shoulder region. If I change to the prone shooting position I don't really notice much extra recoil therefore, but the wee girl will experience a relatively larger increase in recoil on shooting prone.

Just watch youtube funny videos of "I lent my wee girlfriend my big manly gun" and you usually see failure to make firm shoulder contact. All it says is, "her boyfriend is an idiot and will he never get a girlfriend who enjoys shooting with him".

Your wee friend should maybe shoot standing or kneeling, with a firm shoulder contact, even though he may feel safer handling a big gun lying prone. But things are not what they seem.

Of course, especially in shooting positions that allow your body to recoil back with the gun, having a gradual power release from the suppressed gun will allow your body to absorb the recoil more widely and move back with the gun. On an accuracy point, the suppressor allows you to hold the gun less firmly against your body, and thus less heartbeat oscillation is transmitted to it.

Hope this is helpful.

He is a seasoned shooter that weighs about 45kg dripping wet. And I agree that holding it tight back into the shoulder is what he is supposed to do. I am certain that he is as well, but the gun is nearly the same size he is.....and most of his shooting is at a bench standing up. The way I see it, the harder you pull the gun into your shoulder the more it makes the two masses (shooter and gun) into the same mass to be affected by recoil. Thus increasing the resulting rearwards acceleration by increasing the mass.

Originally Posted by timattalon

He is a seasoned shooter that weighs about 45kg dripping wet. And I agree that holding it tight back into the shoulder is what he is supposed to do. I am certain that he is as well, but the gun is nearly the same size he is.....and most of his shooting is at a bench standing up. The way I see it, the harder you pull the gun into your shoulder the more it makes the two masses (shooter and gun) into the same mass to be affected by recoil. Thus increasing the resulting rearwards acceleration by increasing the mass.

@timattalon,
Yes, energy transfer butt-to-body is hampered by an air gap. And one misses out on the longer power transfer time offered by the suppressor.

@timattalon E=mc2 is Energy = mass x (speed of light)squared and is not relevant to this discussion.

The post above by gadgetman has the relevant equations.

Energy is energy, work is energy expended over time, force felt (work) is affected by the total energy expended and the time/pattern it is released over..... suppressors alter the pattern of energy expended over time which changes the perception of felt force. They do not alter the total amount of energy released.. and they have no effect on converting energy in felt recoil into a different direction.

The best example I can think of would be a compressor storage tank. Dumping the contents over a short time increases the felt force.... the same amount of energy is released with a smaller valve over a longer time...

Muzzle brakes on the other hand convert some of the total energy released into forwards force by redirecting some of that energy in the opposite direction.... different process....

Originally Posted by Sidney

Energy is energy, work is energy expended over time, force felt (work) is affected by the total energy expended and the time/pattern it is released over..... suppressors alter the pattern of energy expended over time which changes the perception of felt force. They do not alter the total amount of energy released.. and they have no effect on converting energy in felt recoil into a different direction.

The best example I can think of would be a compressor storage tank. Dumping the contents over a short time increases the felt force.... the same amount of energy is released with a smaller valve over a longer time...

Muzzle brakes on the other hand convert some of the total energy released into forwards force by redirecting some of that energy in the opposite direction.... different process....

Though, because the gases cool in the suppressor, some of the kinetic energy is turned into heat energy and dissipated. This is why an attached suppressor is not an entirely closed system.

Originally Posted by gadgetman

Though, because the gases cool in the suppressor, some of the kinetic energy is turned into heat energy and dissipated. This is why an attached suppressor is not an entirely closed system.

That would alter with the latent heat inside the suppressor which is quite a bit especially after a few shots with a suppressor cover on.

Also on how fast the heat is transferred, a titanium one I fired a shot through on a 338 LM nearly burnt my hand after only one shot