RecoilRob
Member
According to Armalite...we've all been wrong about this, and after reading their reasoning...I've got to agree. http://www.thetruthaboutguns.com/20...l-piston-system employing-current-ammunition/
So...AR's are NOT 'direct impingement' operating systems
- Thread starter RecoilRob
- Start date
- Status
someguy2800
Member
In Eugene Stoners patent he referred to the impinging parts as a piston and cylinder.
https://www.google.com/patents/US2951424
I guess I would argue that since the gas is pushing directly on the gas key which is part of the carrier without going through any connecting parts it is direct impingement, but it just has a piston an cylinder built in. To call it anything else just looks like a marketing ploy trying to sidestep around the term which now has negative connotations.
https://www.google.com/patents/US2951424
I guess I would argue that since the gas is pushing directly on the gas key which is part of the carrier without going through any connecting parts it is direct impingement, but it just has a piston an cylinder built in. To call it anything else just looks like a marketing ploy trying to sidestep around the term which now has negative connotations.
chicharrones
needs more ammo
"TECHNICAL NOTE 54: DIRECT IMPINGEMENT VERSUS PISTON DRIVE" from the TTAG link.
I wish I would have downloaded all the ArmaLite technical notes when they were still available from the previous ArmaLite website. I only have 8 of them on my computer.
GBExpat
Member
<shrug> They are welcome to say that where the gas blasts directly into the bolt carrier is actually a tuna sandwich and, therefore, that makes the whole operation a lunch counter rather than direct impingement configuration. 
It's true they can call it what they want. Using that logic, since the gas impinges directly on the piston of an AK, you could say the AK uses an direct impingement system.
However, the inventor and the U.S. Patent Office define the AR system as something else to protect the inventor's intellectual property and therefore what it is called is important
However, the inventor and the U.S. Patent Office define the AR system as something else to protect the inventor's intellectual property and therefore what it is called is important
Proper definitions are also important when discussing a subject. Otherwise, an exchange of information and sharing of knowledge cannot take place.
The AR is a complex machine. It's not a complex machine because it's complicated or because it's workings are difficult to understand. It's a complex machine because it's made up of more than one type of simple machine, such as an inclined plane, pulley, lever, etc. One cannot describe or understand the workings of a machine unless one knows what parts make up that machine. In order to explain how an AR works, saying "that stuff hits that thing and makes it go" is wholly inadequate.
To insist that it doesn't matter how something is defined in order to differentiate it from something else, shows a lack of understanding of necessity for clear and concise communications
The AR is a complex machine. It's not a complex machine because it's complicated or because it's workings are difficult to understand. It's a complex machine because it's made up of more than one type of simple machine, such as an inclined plane, pulley, lever, etc. One cannot describe or understand the workings of a machine unless one knows what parts make up that machine. In order to explain how an AR works, saying "that stuff hits that thing and makes it go" is wholly inadequate.
To insist that it doesn't matter how something is defined in order to differentiate it from something else, shows a lack of understanding of necessity for clear and concise communications
Boils down to this - the gas is directed into a gas cylinder, where it simultaneously presses the bolt against the cartridge case head and also moves the bolt carrier backwards starting the action cycle. The bolt has gas rings on it to seal, the bolt tail is the piston head, and the gas cylinder is the actual part which is propelled.
Most gun owners lacking a sense of actual mechanical engineering simply don't understand it. Study a radial aircraft motor where the crankshaft is anchored to the frame and prop bolted to the cylinders and you see it. Yes, in that motor, the "block" spins - not the pistons, which remain stationary. It's the cylinder which goes up and down. In the AR, the cylinder is the moving part, which is where many who look at it don't understand.
It's a "stationary" piston design - eliminating the long rod and incorporating the working cylinder into the bolt carrier.
As for where the gas goes when done, it's expelled out the two exhaust ports on the side of the bolt carrier out the ejection port. So, how does the bolt face and action get dirty? By gas exhausted PAST THE BRASS CASING as it's extracted, just like any other blowback or delayed action gun. Only manual actions get clean brass out the chamber, even a 10/22 Ruger dirties the brass. Shoot it enough and it builds up on the action, too. No gas cylinders at all.
Those of us who have owned HK91's suffered the same issue, gas directed around the brass case dirties up the action - not to forget the chamber is fluted to float the case out since the bolt head doesn't turn. Gas does very much blow out the chamber, those who shoot silencers will be more than happy to demonstrate it - their guns have a very large gas trap screwed to the barrel forcing the remaining pressure back thru the action.
It takes a large deficit in mechanical knowledge to misunderstand that and blame the gas tube for it. That is only fed thru a .063" port in the barrel, the barrel is .223" at the throat. Yet some can't do the math.
It can be called whatever - it doesn't change the facts.
Most gun owners lacking a sense of actual mechanical engineering simply don't understand it. Study a radial aircraft motor where the crankshaft is anchored to the frame and prop bolted to the cylinders and you see it. Yes, in that motor, the "block" spins - not the pistons, which remain stationary. It's the cylinder which goes up and down. In the AR, the cylinder is the moving part, which is where many who look at it don't understand.
It's a "stationary" piston design - eliminating the long rod and incorporating the working cylinder into the bolt carrier.
As for where the gas goes when done, it's expelled out the two exhaust ports on the side of the bolt carrier out the ejection port. So, how does the bolt face and action get dirty? By gas exhausted PAST THE BRASS CASING as it's extracted, just like any other blowback or delayed action gun. Only manual actions get clean brass out the chamber, even a 10/22 Ruger dirties the brass. Shoot it enough and it builds up on the action, too. No gas cylinders at all.
Those of us who have owned HK91's suffered the same issue, gas directed around the brass case dirties up the action - not to forget the chamber is fluted to float the case out since the bolt head doesn't turn. Gas does very much blow out the chamber, those who shoot silencers will be more than happy to demonstrate it - their guns have a very large gas trap screwed to the barrel forcing the remaining pressure back thru the action.
It takes a large deficit in mechanical knowledge to misunderstand that and blame the gas tube for it. That is only fed thru a .063" port in the barrel, the barrel is .223" at the throat. Yet some can't do the math.
It can be called whatever - it doesn't change the facts.
It's like a lunch counter, where the seats are commodes.<shrug> They are welcome to say that where the gas blasts directly into the bolt carrier is actually a tuna sandwich and, therefore, that makes the whole operation a lunch counter rather than direct impingement configuration.
Dain Bramage
Member
Motors of that type are generally called "rotary". The ones with stationary cylinders and rotating cranks are called "radial". I mean if words matter, and all that.
First, we would hope that more propellant gas is moving down the barrel behind the bullet than is passing through the port and being directed back towards the bolt.
Second, the amount of fluid that passes through a 0.063 inch diameter port at tens of thousands of pounds per square inch roaring past at thousands of feet per second is considerable. The bore may have much greater cross-sectional area, but by the time the bolt unlocks and the case starts to move backwards, the pressure is greatly reduced and the rearward velocity of the propellant gasses comparatively tiny.
Third, after seven semesters of mathematics; calculus and beyond, I think I can handle the math.
chicharrones
needs more ammo
World War I vs. World War II and all that.
I did understand what Tirod was meaning, though.
I read the link, this Armalite Company is not the original that developed the weapon, or the company that Stoner worked for. Armalite is basically a brand name that was purchased because of its name recognition within the shooting community.
Mark Weston, the Armalite President, has a problem, and it is not going to change by convincing the public that the AR15 is not a direct impingement weapon. His problem is, the US Army is trying to find a different rifle, a different cartridge, and a direct piston one at that. Direct impingement is a dirty system, blows exhaust directly into the mechanism, and that is one reason the M16/M4 is such a maintenance heavy sidearm. Armalite is selling lots of AR15 rifles because, it happens to be similar looking to the standard service rifle of the US Army. If the Army does switch to a totally different rifle, Armalite's sales will be impacted. Armalite, and all the other AR15 makers, are going to have unknown patent, trademark, and licensing issues to contend with if they want to make a copy of any new service rifle. Just like the latest fashion trend, all the wannabees will want the newest rifle, not last year's nasty old rifle.
So what I read in the link, is not only a re defining of that filthy operating system, direct impingement, but an exposition on the evils of gas piston systems.
Mark Weston and all the AR15 fan boys might as well bay at the Moon for all the influence they are going to have about the selection of the next service weapon.
Mark Weston, the Armalite President, has a problem, and it is not going to change by convincing the public that the AR15 is not a direct impingement weapon. His problem is, the US Army is trying to find a different rifle, a different cartridge, and a direct piston one at that. Direct impingement is a dirty system, blows exhaust directly into the mechanism, and that is one reason the M16/M4 is such a maintenance heavy sidearm. Armalite is selling lots of AR15 rifles because, it happens to be similar looking to the standard service rifle of the US Army. If the Army does switch to a totally different rifle, Armalite's sales will be impacted. Armalite, and all the other AR15 makers, are going to have unknown patent, trademark, and licensing issues to contend with if they want to make a copy of any new service rifle. Just like the latest fashion trend, all the wannabees will want the newest rifle, not last year's nasty old rifle.
So what I read in the link, is not only a re defining of that filthy operating system, direct impingement, but an exposition on the evils of gas piston systems.
Mark Weston and all the AR15 fan boys might as well bay at the Moon for all the influence they are going to have about the selection of the next service weapon.
grampajack
AR Junkie
- Joined
- Mar 31, 2016
- Messages
- 1,714
While it's not exactly apples to apples to compare ar15s to other direct impingement rifles (apples to apple-pears maybe?), it's also downright asinine to compare them to traditional gas piston operated ones (clearly apples to oranges).
First and foremost, EVERY semi automatic gun has a piston somewhere if you look hard enough. Using Armalite's own terminology, the gas cup built into the carrier of traditional DI guns is in fact a movable cylinder with a fixed piston (the gas tube being the fixed piston in that case), and therefore direct impingement doesn't even exist. See how ridiculous we can get if we try hard enough?
It's obvious that direct impingement has gotten a bad reputation, which is in and of itself absurd, and now offended individuals are trying to rebrand the ar15 as being synonymous with "gas piston operated" for the sake of convincing people it's something totally different than what it is. In fact though, it's closest to direct impingement, and since the gas impinges directly on the carrier I don't see any problem whatsoever calling it a direct impingement system. Yes, using the bolt tail as a "stationary piston" (Stoner's term) is very clever, but it doesn't exactly change the nature of the beast.
Long story short, if Armalite sent me such an unsolicited memorandum I would politely tell them where they could stick it. They can split hairs and bend the facts all they want but they certainly can't expect the shooting industry at large to go along with their self serving nonsense.
First and foremost, EVERY semi automatic gun has a piston somewhere if you look hard enough. Using Armalite's own terminology, the gas cup built into the carrier of traditional DI guns is in fact a movable cylinder with a fixed piston (the gas tube being the fixed piston in that case), and therefore direct impingement doesn't even exist. See how ridiculous we can get if we try hard enough?
It's obvious that direct impingement has gotten a bad reputation, which is in and of itself absurd, and now offended individuals are trying to rebrand the ar15 as being synonymous with "gas piston operated" for the sake of convincing people it's something totally different than what it is. In fact though, it's closest to direct impingement, and since the gas impinges directly on the carrier I don't see any problem whatsoever calling it a direct impingement system. Yes, using the bolt tail as a "stationary piston" (Stoner's term) is very clever, but it doesn't exactly change the nature of the beast.
Long story short, if Armalite sent me such an unsolicited memorandum I would politely tell them where they could stick it. They can split hairs and bend the facts all they want but they certainly can't expect the shooting industry at large to go along with their self serving nonsense.
Howard Roark
Member
FYI, Mark Westrom sold Armalite to S.A.C. in 2013.
Well, he is entitled to making a profit and I hope he did so. I have a couple of Armalite 223 rifles, I have high regard for the quality of the Bushmaster, Rock River, and Armalite AR15's that I have owned and shot when I was shooting a 223 service rifle. I much preferred the 308 M1a to them all though, and think it was a mistake when the M16 replaced the M14. There has been a whole lot of water under that bridge.
The truth is never ridiculous (although I'd like to point that the gas cup is really a piston and cylinder). What the AR has that DI rifles don't is an expansion chamber.
I ask this- Did the original Armalite Company ever call it a DI system? Did Eugene Stoner? Colt? Nope. So it's not a redefining of what the system is, it's a correction. What I find ironic is here we folks who don't have an understanding of how machines work trying to explain how machines work to those who do. So I'm going to bow out of this and let those who stubbornly refuse to learn once again carry the day
chicharrones
needs more ammo
Yep. Just like Springfield Armory, Henry Repeating Arms, Triumph Motorcycles, etc. etc.
chicharrones
needs more ammo
The truth is in the rings. Pistons can have rings. Where are the rings in the AR gas system? On the bolt tail.
In truth it doesn't matter much to me as I just call it an AR gas system as I can't bring myself to say "impingement" in public.
In truth it doesn't matter much to me as I just call it an AR gas system as I can't bring myself to say "impingement" in public.
Last edited:
The "direct gas action" was invented in France by Rossingnol and involved an action that was actuated by gas tapped from the barrel and directed back to impinge on the bolt, bolt carrier or slide assembly. The French ENT and MAS rifles along with the Swedish Ljungman M42 used such a system. In each case, gas was vented from the barrel and impinged on a "cup" in the bolt carrier to actuate the action. In the AR-15, the gas is tapped from barrel and directed back to a gas block which then directs the gas to an interference mechanism (i.e the piston rings on the back of the bolt) that actuates the action.
The distinction between the ENT, MAS, M42 and M-16 and rifles like the M1 Garand, M1 Carbine, FN FAL, AR180 and the like seems to lie in what whether or not the propellant gasses tapped from the barrel are used at the point where they are tapped (and thus isolated from the rest of the rifle's action) or if they are returned to the vicinity of the breach.
grampajack
AR Junkie
- Joined
- Mar 31, 2016
- Messages
- 1,714
The "truth" in this case is that the Stoner system is just a variant of direct impingement. The presence of an expansion chamber doesn't make one iota of difference. What counts is that the gas impinges directly on the carrier, moving it to the rear without any intermediary, namely a piston. Hence the "direct" in direct impingement. It's not blowback, it's not piston operated (at least in the traditional sense), so therefore it must be direct impingement.
BTW, the designer and manufacturer don't get to unilaterally tell everyone what to call their products. We, the consumers, make those decisions for ourselves. It's really meaningless what it says in the patents, etc. What matters is how it fits into the wider spectrum of other firearms, what it's most similar to, and that's how it got classified as DI, and that's why it will always remain in that classification. Armalite is just trying to muddy the waters for marketing purposes. They don't want to use the term direct impingement because some people (ignorant people I might add) dismiss it as unreliable, so they're trying to bully everyone into adopting new, less controversial terminology. That's their problem, not mine.
You might stop to ask yourself why they're so hellbent on making people call it a piston operated system, as opposed to something more accurate, like "Stoner Operating System." It's because they as marketers know that piston, to the ignorant public, is equated with reliability. They want people to think of it as the same thing as any ordinary piston operated rifle.
ETA: Again, just to illustrate how ridiculous this all is, we could just as easily arbitrarily reclassify the Tavor as DI. We'll just say that the piston is in fact an extension of the carrier, and therefore the gas impinges directly on the carrier.
But we all know that the Tavor is piston operated, despite the presence of a gas tube, just like we all know that the AR is DI. If it walks like a duck and quacks like a duck, by golly it must be a duck.
Last edited:
There is an early Gun's magazine about the Armalite rifle, as I recall the bolt mechanism in the AR15 was designed around existing patents. Armalite did not want to pay royalties, and had to come up with a design that circumvented the claims of other rent seeking Corporations.
I don't recall it being called DI at the time, but then, not calling it DI might have deflected patent lawsuits.
If this was a legal definition, then there are Judges who could decide what direct impingement means. Or what the definition of "is" is. Anyone remember the great legal minds who worked on that issue? As it is, Corporations are not restricted in redefining nor in making a case why
This is not a Cola, it is the real thing or,
This is not a Yogurt, it is a lifestyle or,
This is not a Car, it is an experience or,
This is not a cigarette, it is freedom, or,
etc, etc, etc.
So what? You might as well redefine blowback operation as inertially delayed unlocked disposable internal piston gas operation. It's not wrong, but it's nowhere near useful.
I think it's just Armalite making up their own definitions so they can "correct" others, Humpty Dumpty style.
I think it's just Armalite making up their own definitions so they can "correct" others, Humpty Dumpty style.
- Status
