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Compensator Question


Bear1142

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What do I want to know? Personally? I want to know the design spec's for a comp that totally eliminates muzzle flip, reduces rearward felt recoil to a level equal to a .22 rimfire while still maintaining a very high slide velocity. It would be nice if it didn't weigh more then a couple of ounces and was less then an inch in length. Then I would patent the design, CNC a couple 1000 of them, and sell them for a small fortune.

Oh, wait a minute, sorry, just kidding, got carried away for a minute...............

I think the orginial question was basically, "given a static amount of gas pressure and volume, does the effiency of the comp increase or decrease as port length relative to the barrel bore centerline increases or decreases".

Lets narrow things down to a 38 super shooting major, as other calibers and power factor would be different.-----I believe that the first port should be on the large size as previously stated. The remaining ports should be medium to large in size. There is plenty of gas left to do some work. How many more ports depends on other factors like weight of slide and comp/barrel set up.-----Some shooters want less recoil so they opt for some bleeders rather than all ports. They sacrafice some flip for less recoil.-----Some shooters like big comps and light slides and see the dot drop, come up then back down onto target. Others just want the dot to flip a bit.-----One must remember that the comp only works in the beginning when it is under pressure. Once the pressure subsides, the slide cycles and the comp is only dead weight. The slide cycling agains the recoil spring will cause some flip, the comp can not do much at the point.-----Hope this isn't too general. If so, ask more.

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Okay, I've been working on this for quite some time but I'm having some trouble reasoning it out. With respect to compensator design (rifle and pistol), should the chambers on the compensator decrease size or increase in size as they get further away from the muzzle? I understand that with respect to gas flow, there is an inverse relationship between gas volume and gas pressure. As your pressure goes down, you need more gas volume to maintain the same gas flow. How does chamber size affect this? Should your chambers increase or decrease in size to maintain your gas flow?

Erik

I'm in no way an engineer or gunsmith of any kind but it seems to me Erik kind of answered his own question. Given that his statement about "as pressure goes down, you need more gas volume to maintain more gas flow" is true. This would mean that a comp that starts with a large first chamber causing high pressure bleed off would then need the next chambers to decrease in size relative to the lentgh of the compensator. The reason for this would be that the progressing smaller chambers have less room for the gasses to occupy therefore increasing pressure of smaller gas volume.

The best example I have experince with as an open shooter was with a Bedell comp on a 38 super open gun. If a remeber correctly the first chamber starts out large and they get progressivley smaller for the next 2 , but not only were they smaller in length but also width and depth(Dan feel free to correct me if I'm wrong). I didn't get to experiment long with this comp on my gun for long as the gun met with a mysterious end, but after having a few different comps on this particular gun the Bedell comp was most impressive with little to no dot movement and a very soft perceieved recoil.

If you take a look around you will find most comps take on a similar design as above. I don't nessecarily think this is because the comp designers are lazy about coming up with a different design but that this design works.

Of course when it comes to comp design there never will be a perfect over all design. When you factor in all the different bullet, powder, spring, and slide combinations, no one comp will ever work with them all and lets not forget the most finicky part of the whole equation. The person behind the gun.

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WOW! I go away for a day and look what happens. Thanks for all of the thoughts and replies.

Let's make some clarifications to help move this along.

First, I used the term "Compensator" as a general term that covers both compensators and muzzle brakes. I appreciate that the terms have different definitions, but I think a blend of both terms is our ultimate goal. Our first priority is keeping the gun flat. Regardless of how fast the shooter is, if the gun isn't level and back on target, we can't fire the second shot. Once we have achieved our goal of keeping the gun flat (compensated) we want to use any/all of the remaining gases to pull the gun forward or make it soft (brake.) Now, by its very nature, a compensator will also give you some "brake" qualities when the gases hit the baffles before the gas changes direction, but this is not its ultimate goal. So assuming our first priority is keeping the gun flat and our second is making it soft, let's use the term "Compensator" to encompass this goal.

Second, lets reduce as many variables as possible and keep the discussions centered around the actual design of the compensator. The more variables we introduce the harder it will be to focus on the design aspect. I understand there are many other variables that can influence either positively or negatively the handling characteristics of the gun (size, weight, springs, powders, bullet weights, grip strength, etc), but I want to focus the discussion on strictly the design aspect (if this is possible), with the goal of producing the best design absent all the other factors.

Third, I intentionally included rifle compensators in the question because I wanted to see how the design would be affected by a substantially larger volume of gas. Due to the limited volume of gas available, pistol compensators designs are 90% compensator and 10% brake (arbitrary numbers), while rifle compensators seem to have more of a 50/50 or 60/40 breakdown towards being muzzle brakes first. I personally think most of the rifle comp designs have the wrong emphasis and are designed wrong, but they still are quite effective because a rifle cartridge has such a larger volume of gas available that it makes up for the poor design (with some other factors like the weight of the rifle, etc.) So how does the larger volume of gas available affect the design?

Fourth, and no one has touched upon this yet, is the thrusting aspect of the gases. What role does this have? For example, if a baffle is 90 degrees perpendicular to the bore axis, then our gases hit the baffle and make a 90 turn and we have some effect on the gun. What if the baffle, instead of 90 degrees is only 65 degrees with a 25 degree back angle. Now the gas not only hits the baffle and changes direction, but the gas itself is now vectored at such an angle to increase the compensated effect, similar to the "thrust vectoring" technology used by the F-22 Raptor to significantly increase its manuverability. This concepts seems to only apply to rifle compensators as pistols don't seem to generate enough gas volume to effectively use this concept.

So, with these clarifications in mind, lets run with it.

Erik

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Slo-mo video of a comp gun firing: http://www.sscmagnum.de/Video/007tanf.mpeg

Notice how almost all the flip is long after the comp fires.

There is an upper-bound on effectiveness. A well-known smith has told me he once made a comp that worked so well the slide wouldn't cycle. It was considerably larger than what we use today.

I still believe that there is no perfect comp-- there are bad comps and good comps, even comps that are perfect for somebody, but no perfect ones for everybody. Thus the comments from the gun-builders about what do you want and loooking at the whole system.

Now for academic reasons, this discussion could go on forever. There are so many variables to consider.

I believe that the volume and pressure of the gas as-such is far less relevant than getting it's momentum doing useful things-- a small port will get you an upward jet, but without enough room to expand to hit a useful amount of baffle, you won't get much forward pull. A large port will probably generate more forward pull and less upward jet. Forward-slanting the baffle will get less work out of the gas, but maybe in a more useful direction. The angle of the back side of the baffle is also worth considering.

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WOW, what a thread. And no one has picked up on my error about Alex Wakal's F-2- He decreases the size of the chambers as he goes forward not increases them as I erroneously wrote earlier. Also, in rifles, chambers do tend to run bigger than one caliber, probably because they have so much more gas to deal with. I must comment that I did remain mostly in the physics because that was my interpretation of what was requested, but I can never resist traversing into engineering because that is where the practical comes out.

Hey EricW, you go guy! Empirical design is what we already have a bunch of. A more analytical approach could yield a more compact and effective design, but I am quite busy with airplanes and my profession to embark upon that task.

George, I love ya, you read and understood my post too! And then Radical Pistol Designs (sorry, I can not recall your name right now), understands the physics too. THis can be quite a discussion.

Hmm, A few more misconceptions to clear up:

Burning outside the barrel - By the time peak pressure is reached in the gases, which is well before the bullet leaves the bore, the gun powder has pretty well been consumed and the reactions have almost completely gone to completion. All that is left is adiabatic expansion. Now those who remember high school chemistry (that was long time ago for me) know that when a gas decreases in temperature, electrons make quantum decreases in energy from higher to lower energy states and emit photons then. So we see fire as the gases make decreasing energy jumps - as the gases expand. The burning happens, then as the gases travel away, we see the flames. That is why we should point the fire extinguisher at the fuel, not at the flame.

This is not to say that more burning can not occur once the bore is uncorked. The powder is oxygen deficient, so some of the gases (various HC's, H, H2, and CO) are ready to burn some more when mixed with air and ignited. This event gives big muzzle flashes and sometimes flames at the ejection port and/or gas cylinder vent too. But as I say, that requires mixing in some more air from around the muzzle and ignition, usually by incandescent ash particles from the primer back in the rear end of the gas column, so it happens pretty late and largely outside of the brake or comp.

Brakes vs Comps - Semantics, really. It is all about what you want the redirected the gases to do, whether you reduce muzzle rise or recoil. In our current recoil operated Open Pistols, yeah, you need to leave enough recoil to work the gun, and that leaves you some gas to vent in directions to eliminatel muzzle rise or lateral walk. In gas op rifles, we primarily want the push countered by a pull, and most of the effort is put there, with a little spent on controlling muzzle rise or walk.

Changing angles. Hmmm. For our work we tend to have brakes and comps that are made using orthogonal thinking. Yeah, baffles and vent holes at 90 degrees to the barrel axis. Open shotguns have the JP mid barrel mounted brake at larger angles. For .50 BMG rifles and the like, they use bigger angles, and the thought is obviously to get even more direction change on the gases. While it works, these rifles become terribly anti-social to shoot. And the recoil reduction is beyond what we have use for in 9mm Major Pistols. While the rifle rules do not yet prohibit them, if someone shows up with a Major Rifle with backward angle ports, I suspect that it would quickly be banned because no sane RO could follow you closely enough through most stages.

Ah well, food for thought and more discussion.

Billski

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Wow...sounds like rocket science to me... :lol:

It IS rocket science. We are designing a rocket with the powder being our fuel mass and the compensator the (rather inefficient) rocket nozzle. It's Tsiolkovsky's equation and the Navier-Stokes fluid dynamics equations applied to handguns!

The equations for what is happening in the pistol are a lot more complicated than a simple rocket though since we are trying to balance bullet energy, slide and reciprocating parts energy, and rocket nozzle energy not just in a straight line as in a rocket but in an arc about a specific point - angular momentum. On top of that our "rocket" is done burning in a few milliseconds.

Maybe if a company could get some time on a Cray they could model the entire recoil cycle of a comp gun and do some playing around with the comp designs.

Comp chambers - if we follow current designs - need to have the chambers progressively shrink to keep exit gas velocity high.

I shot an entirely new pistol comp design last week. I won't say WHOSE comp it is since I think they are looking to protect the design. I will say I was impressed at it's effectiveness and see a lot of potential with a little fine tuning. It looks very different than anything currently on the market.

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Billski,

There are comps with back angle ports already in use. Bushmaster's Y-comp, TTI eliminator comp, and Z-M's comp.

Recently, I used a TTI eliminator comp on a 308 DPMS rifle at the Superstition Mountain Mystery 3-gun in Heavy Metal (It worked quite well.)

Ohh, and if this thread isn't confusing enough. I haven't even started with my ideas for mass/momentum cancellation comps or active cancellation designs. :o

Erik

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WOW, what a thread. And no one has picked up on my error about Alex Wakal's F-2- He decreases the size of the chambers as he goes forward not increases them as I erroneously wrote earlier. Also, in rifles, chambers do tend to run bigger than one caliber, probably because they have so much more gas to deal with. I must comment that I did remain mostly in the physics because that was my interpretation of what was requested, but I can never resist traversing into engineering because that is where the practical comes out.

Hey EricW, you go guy! Empirical design is what we already have a bunch of. A more analytical approach could yield a more compact and effective design, but I am quite busy with airplanes and my profession to embark upon that task.

George, I love ya, you read and understood my post too! And then Radical Pistol Designs (sorry, I can not recall your name right now), understands the physics too. THis can be quite a discussion.

Hmm, A few more misconceptions to clear up:

Burning outside the barrel - By the time peak pressure is reached in the gases, which is well before the bullet leaves the bore, the gun powder has pretty well been consumed and the reactions have almost completely gone to completion. All that is left is adiabatic expansion. Now those who remember high school chemistry (that was long time ago for me) know that when a gas decreases in temperature, electrons make quantum decreases in energy from higher to lower energy states and emit photons then. So we see fire as the gases make decreasing energy jumps - as the gases expand. The burning happens, then as the gases travel away, we see the flames. That is why we should point the fire extinguisher at the fuel, not at the flame.

This is not to say that more burning can not occur once the bore is uncorked. The powder is oxygen deficient, so some of the gases (various HC's, H, H2, and CO) are ready to burn some more when mixed with air and ignited. This event gives big muzzle flashes and sometimes flames at the ejection port and/or gas cylinder vent too. But as I say, that requires mixing in some more air from around the muzzle and ignition, usually by incandescent ash particles from the primer back in the rear end of the gas column, so it happens pretty late and largely outside of the brake or comp.

Brakes vs Comps - Semantics, really. It is all about what you want the redirected the gases to do, whether you reduce muzzle rise or recoil. In our current recoil operated Open Pistols, yeah, you need to leave enough recoil to work the gun, and that leaves you some gas to vent in directions to eliminatel muzzle rise or lateral walk. In gas op rifles, we primarily want the push countered by a pull, and most of the effort is put there, with a little spent on controlling muzzle rise or walk.

Changing angles. Hmmm. For our work we tend to have brakes and comps that are made using orthogonal thinking. Yeah, baffles and vent holes at 90 degrees to the barrel axis. Open shotguns have the JP mid barrel mounted brake at larger angles. For .50 BMG rifles and the like, they use bigger angles, and the thought is obviously to get even more direction change on the gases. While it works, these rifles become terribly anti-social to shoot. And the recoil reduction is beyond what we have use for in 9mm Major Pistols. While the rifle rules do not yet prohibit them, if someone shows up with a Major Rifle with backward angle ports, I suspect that it would quickly be banned because no sane RO could follow you closely enough through most stages.

Ah well, food for thought and more discussion.

Billski

Just wondering if you have any thoughts on the use of bleeders on pistol comps.

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My guess is that in reality it doesn't matter, but in Theory (that little town where everything works), every port bleeds off gas, so to get the same amount of gas (pressure * volume) in each port (assuming you want that and that it's even achieveable with a bullet in the way), they would need to get larger.

I believe that a large portion of the gasses escape during the first port or two (depending on the acutal port sizes) and most designs attempt to keep the flow velocity up at the subsequent ports. To accomplish this they reduce the size of the ports to keep the flow velocity up despite the decreased pressure/volume of gas they have to work with. Some designs throw in a huge final chamber to get rid of whatever gasses might remain before they exit the muzzle hole.

Good description of a current popular open gun design. This is usually based on the progressive style of comp where the ports get small. Some have asked, what do you do with the left over gas? You just described it. Make the final port/ports bigger. Small bleeders can be machined into the sides of those ports also, this makes it a combination port and bleeder. This offers the most compact and lightest setup. Also, large bleeders can be added onto the end, but they generally add weight.

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WOW, what a thread. And no one has picked up on my error about Alex Wakal's F-2- He decreases the size of the chambers as he goes forward not increases them as I erroneously wrote earlier. Also, in rifles, chambers do tend to run bigger than one caliber, probably because they have so much more gas to deal with. I must comment that I did remain mostly in the physics because that was my interpretation of what was requested, but I can never resist traversing into engineering because that is where the practical comes out.

Hey EricW, you go guy! Empirical design is what we already have a bunch of. A more analytical approach could yield a more compact and effective design, but I am quite busy with airplanes and my profession to embark upon that task.

George, I love ya, you read and understood my post too! And then Radical Pistol Designs (sorry, I can not recall your name right now), understands the physics too. THis can be quite a discussion.

Hmm, A few more misconceptions to clear up:

Burning outside the barrel - By the time peak pressure is reached in the gases, which is well before the bullet leaves the bore, the gun powder has pretty well been consumed and the reactions have almost completely gone to completion. All that is left is adiabatic expansion. Now those who remember high school chemistry (that was long time ago for me) know that when a gas decreases in temperature, electrons make quantum decreases in energy from higher to lower energy states and emit photons then. So we see fire as the gases make decreasing energy jumps - as the gases expand. The burning happens, then as the gases travel away, we see the flames. That is why we should point the fire extinguisher at the fuel, not at the flame.

This is not to say that more burning can not occur once the bore is uncorked. The powder is oxygen deficient, so some of the gases (various HC's, H, H2, and CO) are ready to burn some more when mixed with air and ignited. This event gives big muzzle flashes and sometimes flames at the ejection port and/or gas cylinder vent too. But as I say, that requires mixing in some more air from around the muzzle and ignition, usually by incandescent ash particles from the primer back in the rear end of the gas column, so it happens pretty late and largely outside of the brake or comp.

Brakes vs Comps - Semantics, really. It is all about what you want the redirected the gases to do, whether you reduce muzzle rise or recoil. In our current recoil operated Open Pistols, yeah, you need to leave enough recoil to work the gun, and that leaves you some gas to vent in directions to eliminatel muzzle rise or lateral walk. In gas op rifles, we primarily want the push countered by a pull, and most of the effort is put there, with a little spent on controlling muzzle rise or walk.

Changing angles. Hmmm. For our work we tend to have brakes and comps that are made using orthogonal thinking. Yeah, baffles and vent holes at 90 degrees to the barrel axis. Open shotguns have the JP mid barrel mounted brake at larger angles. For .50 BMG rifles and the like, they use bigger angles, and the thought is obviously to get even more direction change on the gases. While it works, these rifles become terribly anti-social to shoot. And the recoil reduction is beyond what we have use for in 9mm Major Pistols. While the rifle rules do not yet prohibit them, if someone shows up with a Major Rifle with backward angle ports, I suspect that it would quickly be banned because no sane RO could follow you closely enough through most stages.

Ah well, food for thought and more discussion.

Billski

Just wondering if you have any thoughts on the use of bleeders on pistol comps.

Good question. What IS a "bleeder" or its purpose?

Doing some research a while back in some of the newer decreasing chamber size comps, I noticed the carbon/fouling build up and the flow patterns in which they formed. The shape of the chamber and the "ejecta" temperature seemed to dictate the amount and kind of deposits, and where they would be more likely to accumulate.Expanding gases seek an easy way out and hate hidden remote corners. As managing the path of "all" gases is the goal, bleeders of various sizes and shapes can be made to act as a "venturi-guide" to herd gases in those directions for the effect desired. Some people/designers felt that in order to utilize bleeders properly you needed larger volumes/pressures of gas. That thinking only works when trying to make and inneficient design work better. I much rather use "micro-managing" of the gases, chambers and ports to keep the pressures higher and direct them where they will do the best job. Micro-managing also reduces the emphasis on huge volumes of gases, and allows concentrating in the powder burn rate to adjust your gases dwell time in the compensator in relation to your cycling timing requirements. By now you know that some of my design stuff is "propietary" and I can't go into more specific details for obvious reasons.

I also endorse the use of threaded removable/ exchangeable baffle inserts for additional latitude in upgrading/updating the compensator. I got tired of replacing burned out comps. So rather than replacing the comp, you can replace the baffle insert. And if you found the baffle design/shape lacking, just replace it with the one of your choice and see if that works better. Especially nice is the fact that you do not need to change the comp or pay a 'smith' to do it for you.

Also a very useful addition I like is what I call "the floating (round) washer" in front to glean any leftover gases as a final brake. You can see examples in present comps including the STI S-2.

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It seems everyone is basically in agreement that gas pressure and volume, and how you manage it, dicates how well a comp works. It also seems that everyone is in agreement that the design features of the comp are based on converting this energy to a force that counterbalances the normally occuring rearward recoil and muzzle rise. We can probably also agree that muzzle rise is a function of rearward recoil, resulting from the pistol rotating thru the arc of the grip/hand/wrist of the shooter.

So, if we have a given an amount of energy pushing rearward on the pistol then physic's tell us that if we can create an equal force in direct opposition to that energy we would have a pistol with mininal amount of recoil and muzzle flip. We would still have to deal with the mechnical energy produced by the slide impacting the frame at the end of its rearward travel, but for now lets leave that out of the discussion.

Without inducing additional energy at the comp to offset the rearward energy produced by the fired round, it appears that we should be looking at the most effective method of capturing the available energy being presented to the comp, and then directing it in a manner that produces the most opposing force. Since pressure is a function of volume being restricted by space (more volume in a smaller space equals greater pressure) it would seem that by restricting the amount of space the gases have in the comp you would be able to maintain a higher pressure thus giving you a better chance at balancing the opposing force of recoil.

In current comp designs we see immediate porting available to the gases as soon as they leave the barrel creating a situation where an instant massive increase in space allows the gases to rapidly expand and drop in pressure, reducing the available energy to counteract the rearward recoil. This seems to be the opposite of what we should be looking for.

Just as a question, what if we presented the escaping gases with an expansion chamber of a design that allow the gas column to expand to a diameter larger then the bore diameter and then present that column with a baffle, all within a contained enviroment with no porting? We would be maintaining as high a pressure as possible, and managing the energy by driving it into a wall/baffle causing a forward push to counteract the rearward push against the breechface. Since the now much smaller/lower pressure wave front would rebound off the foreward baffle face and move rearwards you could provide a small bleed hole(s) at the muzzle end of the comp to eliminate any meaningful effects of the residual pressure.

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Bob, that is a absolute perfect description of a silencer. They are the most effective pure muzzle brake there is because they do not vent any gas to the atmosphere until all the work is done/pressure dissipated and the round has passed the final exit port.

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It seems everyone is basically in agreement that gas pressure and volume, and how you manage it, dicates how well a comp works. It also seems that everyone is in agreement that the design features of the comp are based on converting this energy to a force that counterbalances the normally occuring rearward recoil and muzzle rise. We can probably also agree that muzzle rise is a function of rearward recoil, resulting from the pistol rotating thru the arc of the grip/hand/wrist of the shooter.

So, if we have a given an amount of energy pushing rearward on the pistol then physic's tell us that if we can create an equal force in direct opposition to that energy we would have a pistol with mininal amount of recoil and muzzle flip. We would still have to deal with the mechnical energy produced by the slide impacting the frame at the end of its rearward travel, but for now lets leave that out of the discussion.

Without inducing additional energy at the comp to offset the rearward energy produced by the fired round, it appears that we should be looking at the most effective method of capturing the available energy being presented to the comp, and then directing it in a manner that produces the most opposing force. Since pressure is a function of volume being restricted by space (more volume in a smaller space equals greater pressure) it would seem that by restricting the amount of space the gases have in the comp you would be able to maintain a higher pressure thus giving you a better chance at balancing the opposing force of recoil.

In current comp designs we see immediate porting available to the gases as soon as they leave the barrel creating a situation where an instant massive increase in space allows the gases to rapidly expand and drop in pressure, reducing the available energy to counteract the rearward recoil. This seems to be the opposite of what we should be looking for.

Just as a question, what if we presented the escaping gases with an expansion chamber of a design that allow the gas column to expand to a diameter larger then the bore diameter and then present that column with a baffle, all within a contained enviroment with no porting? We would be maintaining as high a pressure as possible, and managing the energy by driving it into a wall/baffle causing a forward push to counteract the rearward push against the breechface. Since the now much smaller/lower pressure wave front would rebound off the foreward baffle face and move rearwards you could provide a small bleed hole(s) at the muzzle end of the comp to eliminate any meaningful effects of the residual pressure.

So you want a rocket to fly backwards? Just kidding. How would the barrel link down?

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You mean like the STI TruSight "Expansion Chamber" that the Powers That Be in IPSC decided wasn't a compensator because it didn't have any holes? :wacko:

Gas momentum and what you do with that momentum is the most important thing in my book. Pressure and volume are ancillaries that have to come along for the ride.

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You mean like the STI TruSight "Expansion Chamber" that the Powers That Be in IPSC decided wasn't a compensator because it didn't have any holes? :wacko:

Gas momentum and what you do with that momentum is the most important thing in my book. Pressure and volume are ancillaries that have to come along for the ride.

:D:D:huh::blink::angry:

....Well, it doesn't re-direct the gases upwards. But, wait... it allows the gases to expand and impact a forward baffle before exiting????? Hmmmmm. ;)

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Why haven't we heard from some of the 'expert' folks eavesdropping on this subject, other than try to glean something useful, without contributing?

Stop it, you'll make me blush.

Considering how cheap computers are and how sophisticated medeling technology is for airflow effects..... I'm surprised there isn't some software out there to design brakes and compensators.

BTW: I'll bet the people who design exhaust systems for F1 and superbikes know which end is up in designing things that can pass hot gasses effectively.... the exhaust systems on motorcycles are so precises that they can adjust the torgue range just by changing the insert that goes in the exhast outlet. Way cool stuff....

Edited by bountyhunter
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Bob, that is a absolute perfect description of a silencer. They are the most effective pure muzzle brake there is because they do not vent any gas to the atmosphere until all the work is done/pressure dissipated and the round has passed the final exit port.

:D L.O.L!!!

You have no idea how close you are!?!

In my earlier days of "machine shop" segment at engineering school, I was intrigued by the "maxim" snail design and its self scrubbing effect on gases as the bullet scurried through it. I wondered about just shaving off the top so that it would "make noise" and at the same time redirect the gases upward... Yes, it worked, but there were other problems, including cleaning and longevity. But it planted the seed in my mind. (This was in the early '70's) Since then, on and off I continued to work in perfecting my "micro-managing" principles. It wasn't as simple as transforming a suppressor into a compensator, but it was a beginning. :):):)B)B)

Edited by Radical Precision Designs
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The funny thing about all this is... the important thing about comp design (at least in terms of pistol shooting, cause I don't have experience w/ rifle comps) is not really how efficient it is at trying to keep the muzzle flat, but how consistently does it allow the gun to cycle, and whether or not it influences the muzzle's movement left or right, etc. The point being that a gun that naturally cycles straight up and down, so the dot only moves on one axis, will be the quickest and most accurate to shoot, because you can time the cycling of the gun accurately. Beyond that, a gun that returns itself to point of aim (and doesn't dip, or hang upwards) will also be easier to time.

Some of that is shooter influenced - but I have shot a few designs that simply don't work that way (witness the threads on this forum about dremelling one side of the comp chambers to even out gas flow, etc).

If the design you're using meets *those* criteria, any flatness you get is the proverbial icing, at least from the standpoint of shootability.

Of course, if you can design one that simply doesn't move, but allows the slide to cycle (heh heh) I'm all in... :D

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I like the idea about using a closed system with just an end baffle, but what about directing the gas? Obviously, the gas has momentum that can be used, but why can't we use the momentum aspect combined with the vectoring aspect to increase our efficiency? It may not make a noticable difference on a pistol comp because of the limited amount a gas initially available, but what about a rifle system?

Another problem we've yet to tackle is how to delay or trap the momentum. We've all seen the video showing the gas venting from the compensator long before the slide begins to cycle. Are there any ideas for slowing this process down to time the compensation effects closer to when the slide actually cycles?

Erik

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Actually a silencer, if properly designed, captures all/most of the excaping gases and redirect's them into a large chamber with a series of baffles. It then forces the gases into striking the baffles in an effort to comsume the energy and heat so that by the time the gases excape from the silencer the wave front is balanced with the surrounding air pressure. If does this by using a extra large expansion chamber, and a series of baffles much like a muffler. No wave front/energy pulse exposed to the air, no or little muzzle noise.

If we were to build a comp using a single chamber and baffle system the purpose would be to only allow for enough expansion into the 'chamber' to allow the gas column to grow to a larger diameter then the exit hole so that the the forward movement of the wavefront would strike the baffle. This is controlled by the distance of the baffle from the muzzle (gas under pressure will always expand to fill the available space) and by the inside diameter of the chamber. This effect can be enhanced by using a tapered expansion chamber (Someone mention F1 exhaust systems?), starting at near bore diameter at the muzzle to the full diameter at the baffle. This has to be carefully balanced against excessive expansion which would reduce the gas pressure reducing the momentum of the gases striking the baffle, or the amount of energy imparted in a forward direction to the comp.

The primary difference then becomes thus..........in a silencer we want to allow the gas to rapidly expand and cool reducing the total amount of energy/pressure available, then bounce it off several baffles to absorb the remaining energy, then release it at the lowest possible velocity. In the comp design we are talking about, we want to maintain as high a pressure/energy level as possible, and effectively redirecting it to strike a baffle in a manner that transfers (not absorbs) as much energy as possible then bleed it out of the chamber as quickly as possible in preparation for the next round being fired. A silencer would have no bleed holes, allowing all of the gases to excape thru the exit hole the bullet uses at the lowest possible velocity/pressure. The comp would use a bleed hole(s) back near the muzzle of the barrel to take advantage of the wavefront bouncing off the baffle and returning to the muzzle, while still maintaining a reasonably high pressure/velocity, These gases are then released thru bleed holes on the sides or top of the comp using the remain gas pressure to provide a small jet effective.

But then what do I know, I'm just an old retired guy..............

Edited by Bob Hostetter
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Actually a silencer, if properly designed, captures all/most of the excaping gases and redirect's them into a large chamber with a series of baffles. It then forces the gases into striking the baffles in an effort to comsume the energy and heat so that by the time the gases excape from the silencer the wave front is balanced with the surrounding air pressure. If does this by using a extra large expansion chamber, and a series of baffles much like a muffler. No wave front/energy pulse exposed to the air, no or little muzzle noise.

If we were to build a comp using a single chamber and baffle system the purpose would be to only allow for enough expansion into the 'chamber' to allow the gas column to grow to a larger diameter then the exit hole so that the the forward movement of the wavefront would strike the baffle. This is controlled by the distance of the baffle from the muzzle (gas under pressure will always expand to fill the available space) and by the inside diameter of the chamber. This effect can be enhanced by using a tapered expansion chamber (Someone mention F1 exhaust systems?), starting at near bore diameter at the muzzle to the full diameter at the baffle. This has to be carefully balanced against excessive expansion which would reduce the gas pressure reducing the momentum of the gases striking the baffle, or the amount of energy imparted in a forward direction to the comp.

The primary difference then becomes thus..........in a silencer we want to allow the gas to rapidly expand and cool reducing the total amount of energy/pressure available, then bounce it off several baffles to absorb the remaining energy, then release it at the lowest possible velocity. In the comp design we are talking about, we want to maintain as high a pressure/energy level as possible, and effectively redirecting it to strike a baffle in a manner that transfers (not absorbs) as much energy as possible then bleed it out of the chamber as quickly as possible in preparation for the next round being fired. A silencer would have no bleed holes, allowing all of the gases to excape thru the exit hole the bullet uses at the lowest possible velocity/pressure. The comp would use a bleed hole(s) back near the muzzle of the barrel to take advantage of the wavefront bouncing off the baffle and returning to the muzzle, while still maintaining a reasonably high pressure/velocity, These gases are then released thru bleed holes on the sides or top of the comp using the remain gas pressure to provide a small jet effective.

But then what do I know, I'm just an old retired guy..............

:D:D:DB)B) L.O.L. !!!!!!

Retired from what to what????? Tell us another story!!!!!! Old 'smiths don't retire they just turn it into a "paying tinkering hobby"....

Anyway while "tinkering in my early formative days of engineering schooling" I built this "thing" shaped like a silencer. It even had a removable snail baffles assembly that came out from the rear for cleaning, etc.. It only had three angled bored ports at the front/top about 1/2" from the front exit hole. Yeah, it made noise and reduced flip some, but nothing outstanding. And, just like a supressor "can" it got hot very fast, and the baffles would foul up quickly too before they burn out, as they were rather thin. In those days (early '70's) competition comps styles were limited to some machining either built into the front of the barrel or attached, similar to Hig Standard .22 cal or Walther "drilled holes" compensators. I remembered going over to Austin Behlert with my first comp design for a 1911 (45 ACP) that looked like a weight with a slant cut to an inside expanding chamber screwed into the front of the barrel making it look like a long slide, and Austin looking at it giving me a hard time and laughing. He said I had to much "free time" in my hands, but that I should continue and maybe some day somebody might have use for one of those things...

Various116.jpg

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"Most all recoil compensators are made by conventional or CNC milling machines using the “trial and error” method to determine what ports to use and where to put them."

"...designed from scratch using one of the most powerful fluid dynamics software programs available today."

"Due to the pressures incurred while shooting a modern firearm and the incredibly short time span involved, special software had to be utilized. Other items that share these characteristics are rocket fuel delivery systems and ultra-high pressure water and steam applications."

"...uses four separate chambers with four different impacting plates to redirect and channel the intense high pressure found in a discharging cartridge. Other generic compensators have large rectangle ports and a combination of holes drilled at various places."

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Flex, all their rhetoric aside, check out the video for the .38 Super. Looks like it flips exactly like any other comp design, to me... The .500 S&W stuff is pretty impressive, but things with slides are going to flip some, regardless of what you do, simply because of the slide's movement (and stopping of movement).

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Well sure... a slide is going to have to stop, then change directions.

That just isn't what the question here is about, is it?

Everybody is saying how nobody has put this comp stuff on a computer program and ran the numbers. Well, these guys did.

I don't know how well their stuff worked. As I understand it, the comps they had were heavy. If so, they wouldn't be likely to catch on for USPSA/IPSC pistols. But, this thread is talking about comp theory. And, not just for Open handguns.

It may just be a good basis for a rifle platform?

It sure seems like the stuff that Erik (Bear1142) is asking about has been addressed by those guys. To what extent...I don't know.

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As I have alway's thought, the comp works good, the gun stay's flat & only has flip after the slide bottoms out against the frame at the rear. If you run a light spring it hits harder & has more flip, but a spring that just lets it kiss the frame will have less flip.

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