If one of the biggest problems with normal direct impingement

But carrier tilt isn't a problem with direct impingement

>>32716844
Unless you're talking about the Stoner system, which isn't the same thing, then yes it is a problem.

>>32716961
I always thought direct-impingement was a bad way to describe the Stoner system.

>>32717184
Hence why I said it's not the same thing.

>>32717689
OP pic looks like the stoner system to me.

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>>32717703
If it were, the gas tube would go down and direct gas in line with the bolt, as was the point of it over the traditional system.

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>one of the biggest problems with normal direct impingement systems is carrier tilt

First time I'm hearing this

>>32717873
>First time I'm hearing this

Yep, sounds like horseshit to me, as well.

>>32717873
>>32717938
Why would Stoner make a way more expensive gas system with the goal of applying force on the bolt in line with the barrel, if it wasn't a problem?

>>32718028

Other than to incorporate Mel Johnson's bolt, in lieu of a tipping bolt/inclined plane locking?

We could say- "Just to be fucking different"...But let's go with-"in order to incorporate a system by which the recoil and operating forces were directly in line with the bore of the firearm as well as the buffering mechanism in order to reduce felt recoil and muzzle climb"

Other than the Stoner/Johnson system, the majority of DGI firearms all would seem to "suffer" from the assumed malady. And there are a plethora of them.

Yet they still work just peachy.

The Ljungmann/French "Adductor" mechanism is quite old, and well thought out, contrary to a lot of nonsense floating about out there. The French work on direct gas impingement predates many, if not most self loading mechanisms.

>>32716722
Because no one uses direct impingement anymore

>>32718239

"Kind Of", but at that point hairs are being split, and finely.

>>32717184
>I always thought direct-impingement was a bad way to describe the Stoner system.

That's because it's not DI, it's coaxial gas piston. It's hard to be DI if you have piston rings.

>>32718870

The system could work without rings, but it'd require matching the bolt to carrier, which is inefficient.

Otherwise, you are mostly right.

>>32718219
But couldn't having a split gas tube acting on both sides of the bolt keep the advantages of Stoners in line system, reduce its complexity, and keep the action cleaner at the same time?

>>32718028
Just going out on a limb here but maybe its to make sure that the chamber is locked on tight until the bullet leaves the barrel, might increase accuracy or something.

>>32719112

You're adding another gas tube, and claiming "reduced complexity".

Take a step back and consider that, as the basic versions use "one".

Then explain how "two" gas tubes would "keep it cleaner", considering that with proper propellants it's gas system is damn near self scouring. .

>>32719126

That has nothing to do with the method of unlocking, and all to do with how the breech interfaces with the bolt/breeching mechanism.

To put it in non gun terms~
"How a door swings is based on it's hinges, not it's deadbolt".

>>32719173
I'm not saying two full gas tubes, but one gas tube that forks into two for the last bit of travel. It's just a tiny extra piece of metal. If the AR15 was as clean as you claim militaries wouldn't be adopting gas piston guns left and right in the last few decades.

>>32719343

It's still "two", bifurcated or not.
Be aware, Colt offered a "gas piston" AR-15 in '68, and it was found to be a solution to a problem that did not exist.

Then the Stoner 63, and AR-18 were offered, to little applause.
Only the AR-18 lives on in a much mangled form as the LA85A2, and some SAR 80 variants. I owned an AR-18, and while it was a wonderful little carbine, it did nothing a M-16 would not, while being mechanically more complex. It's sole advantage from a manufacturing standpoint, was it could be whacked out of sheet metal.

Anyhow~

Much of gun marketing is based on that magical premise.
"selling a solution to a non existant problem".

>>32718993
>The system could work without rings
No, it couldn't.

>>32719504

Yes, it could.

In the same way hydraulic and pneumatic spool valves do.

>>32719552
No, it couldn't. The biggest reason for the rings being used for a seal is to make up for any difference in the coefficient in thermal expansion of the materials. It's infeasible to match them in a system that gets as hot as an AR-15 BCG can.

>>32719393
But wouldn't it be a direct improvement over traditional DI guns for very little extra cost?

>>32719805

You're assuming the bolt carrier and bolt would not expand at the same rate, even though they are similar materials.

Meanwhile, the use of steel spools in aluminum valve bodies is industry practice in hydraulic and pneumatic systems. Including ones where high heat differential is more than likely.

Now, I could go into what you'll find in air conditioning systems as well, in regards to this. No rings.

Rings, in piston engines, compressors, etc are used to allow for manufacturing tolerances, and allow a modicum of "fudge factor".

They are not mandatory in a gas system such as the M-16/AR-10, assuming the manufacturer laps the piston to the bolt carrier.

And even then, the "lapping" does not have to be that close. Nowhere near the tolerances one finds in an IC engine.

The three rings one sees in an AR-15 are an example of over-engineering to ensure reliability, rather than engineering to ensure simple function.

>>32720012
Every single spool valve I have seen has some sort of seal. Usually just an o-ring but sometimes more exotic as required.

>>32719893

Not really, as the existant systems are already (relatively) absurdly reliable. More time would be better spent working on improving priming or propellants, than trying to reinvent the wheel in this case.

>>32720012
>Rings, in piston engines, compressors, etc are used to allow for manufacturing tolerances, and allow a modicum of "fudge factor".
Stop talking about what you don't know about.

>>32720034

And yet the one I will soon replace on a hydraulically actuated lift, has none (save the ones that connect the lines to the cylinders) possess any form of seal.

Also, in the literally hundreds of automatic transmissions, fuel scheduling units and hydraulic control assemblies I have dealt with, I have never seen a ring seal of any form on a valve body spool.
Rather, you will find a shallow groove milled where it is expected the fluid itself will do the sealing.

Again, a married bolt and bolt carrier, in a Stoner/Johnson type gas impingement system does not need rings to function. They are merely a concession to manufacturing and interchangability.

>>32720117
>Again, a married bolt and bolt carrier, in a Stoner/Johnson type gas impingement system does not need rings to function.
Build it, then.

>>32720117
A matched bolt/carrier systme in an AR will either be so lose that it starts failing or be tight enough to actually seal and bind up in a couple shots.
High pressure gas, fouling, and heat requires rings to seal effectively. Rings are not simply done as a manufacturing concession but serve a purpose.

>>32718993
>>32719504
>>32719552
>>32719805
>>32720012
The funny thing is that I've been running one of my ARs without any gas rings.

Why?

It's so fucking overgassed it's hilarious. It runs just fine, hot or cold. Hot enough to get the gas tube past blue.

Also, Meplat is correct.

Even then, the "heat expansion" isn't that big of a problem. Over 1" diameter part, it'll grow 0.001" per 100 degrees Fahrenheit. With the size of the AR bolt and BC, even going up 400 degrees F, you're looking at less that 0.001" expansion.

BUT WAIT

THERE'S MORE!

The bolt and BC are also heating up at a similar rate. So heat expansions end up making the BC bigger as well; the external dimensions of the carrier grow, so does the hole diameter.

So yes, you can get an AR to work without rings for multiple reasons and even in multiple ways (regular gas and tighter fit, or stupid overgas and regular fit).

>>32720069
I'm sorry, I seem to have confused you.

Would you like pictures instead?

>>32720189
No, I'd like you stop playing engineer on the internet.

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>>32720217
[newfaggotry intensifies]

you have no fucking clue who you're talking to or what you're talking about, and it's hilarious

>>32720252
I don't care who he is unless he works for the powertrain engineering department at an auto manufacturer. The engine in your car doesn't use piston rings because it's fun, it's because it's a complex environment that requires a high level of sealing at varying temperatures. Fitting is virtually impossible and is only ever seen on very small, high speed engines (model cars, for instance).

>>32720137

Again, it's been done, By Armalite, then Colt

The "rings" exist to allow bolts and bolt carriers to be easily swapped. Not to make the thing work.

>>32720163
Did the same trick with an early SP-1, back in 91. And yes, the AR 15 is fed WAY more than it can eat, which is why it has all the holes in the side of the bolt carrier. So when the bolt commences the unlocking process, it exposes the ports in the bolt carrier to vent the significant volume of excess gas. Inertia does the rest.


A reasonably well oiled SP-1 with a DIAS will fire FA, a 120 round Chinese drum with no rings on the bolt for quite a long time, and will actually work better, to a point.

>>32720308
>And yes, the AR 15 is fed WAY more than it can eat, which is why it has all the holes in the side of the bolt carrier. So when the bolt commences the unlocking process, it exposes the ports in the bolt carrier to vent the significant volume of excess gas.

Indeed. However, some manufacturers will size gas ports (also spring strengths, buffer weights, and bolt carrier cuts) to run a little softer. Obviously more than enough gas to cycle even if the ammo isn't great or if it's cold and dirty (usually) but I have a few guns that don't even open all the way without gas rings, but run like a swiss watch with rings.

Preaching to the pope but yeah, with the anons in this thread, it can't hurt.

did OP confuse stoner-system AR's with piston AR's?. Carrier tilt happens when there's a significant off axis force on the bolt carrier. That only really only happens in piston AR's.

>>32720388
Yes, OP dun goof'd.

Standard gas impingement ARs have no carrier tilt at all.

Just take a look at the skeleton AR Jerry Miculek was shooting. You can see the BCG flying around literally in mid-air through the gun, straight back and forth without a wiggle or a wag.

>>32720388
>>32720409
I never said ARs did. I was referring to traditional DI systems, where the gas slams into the bolt above the barrel, and causes carrier tilt.

>>32720425
Oh.

My bad, I dun goof'd then.

https://www.youtube.com/watch?v=BLadEilZCpY

Have the neat video I mentioned in any case.

>>32720300

Son, not going to beat you over the head, but if you own or have shot any recent Ruger firearms that worked, I'll say "you're welcome".

I can post a whole books worth of stuff I've worked on, just firearm related. And then we get into aircraft, and armor. Then artillery.

Really, just go play with the stuff, don't take my word for it. You'll see.

>>32720353
And that is the really neat part of that system, in that you can fuck with it so much, and it will still try to work.

I'm so wishing I bought more MAS 49's when they were $100.00 just to play with them.

>>32720479
I don't care about any of that. Post books noting that automotive piston engines are manufactured with rings because they want to get lazy with their tolerances. I'll wait.

>>32720425

Again , it's a non-issue. The carrier movement in relation to the gas impetus is in line.

>>32720479
>>32720530
I've handled a Hakim and I would have loved to fuck with them more. From what I hear it sounds like all fun and games but then you get gas in the eyes. Apparently this is a more pressing issue than any tilting.

I do like to tinker with my ARs. Made a few gas blocks, working on an LR-300 (AR-15 where the gas tube and gas key never separate, you might've heard of it, spring around the gas tube so no buffer tube) thing and I even have a concept gas block that would auto-regulate, a bit like an M14 piston. Would probably be useful in conjunction with them quick detach suppressors.

File: Super 60 no rings.jpg (650KB, 1016x1024px) Image search: [Google]

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>>32720493

Post images of automatic transmission valve bodies with ring seals. I'll wait.

Also, have an engine, with no rings.

>>32720530
But carrier tilt is an issue, or every military on earth would be using simple cheap 223 DI rifles.

>>32720565

The M-14 system was the old "White" gas system. Immensely interesting, but ammo sensitive. You also saw it in use with the M-60.

If you knew you were using a low residue propellant and were meticilous about cleaning it could work.

The amusing part about the "White" system is it's found in use on steam engines, well before cartridge arms, and in an offhand variant, in internal combustion engines.

Always fun to see how "new" tech has been done before. .

>>32720628

You are assuming every military uses unerring logic in their decision as to what they use, instead of a jumble of nationalistic and political shitbaggery.

Still, if you look hard, most nations are either using a variant of the M-16, the AR-18 or the Kalashnikov (which is in itself mostly a Garand/Browning mashup)

>>32720668
Nothing new under the sun. I mean "similar" in pretty large quotation marks, my design is honestly more loosely inspired than "similar".

It shouldn't be that sensitive to residue, honestly the part I'm most worried about is the spring. Even if it might end up costing a few bucks, I hear springs can be made from heat resistant, high nickel alloys. Luckily the spring won't have a hard job to do (in a spring's point of view for load cycles and extension/compression), but it'll be more the problem of heat cycles.

If that ends up working, the gas block itself should be pretty damn good at controlling gas to action regardless of muzzle devices and shit.

>>32720723

Like a Nickle Chrome,or a Nickle Vanadium?
There were (is) Nickle Beryllium as well, but I've not dealt with that alloy.

That aside-

Are you expecting to be exposing the spring to sufficient heat to warrant such? Because modern coil springs are absurdly reliable, and then there are multicoil /braided springs.

Will this be a concentric spring, around the valve? If so, and the design warrants, a long, soft spring can take up the slack even after many heat cycles. It's also under a much lower operating stress, overall.

>>32720593
>Post images of automatic transmission valve bodies
A valve body is not an engine
>Also, have an engine, with no rings.
Automotive fuckhead. I already address that those can have no rings.

>>32720857

You first, angry man. Show where I said "automotive".

I said. =>

"Rings, in piston engines, compressors, etc are used to allow for manufacturing tolerances, and allow a modicum of "fudge factor"."

You assumed "car engine". I won't even go into why you did so, since lapped piston/cylinder small engines are not very uncommon.

>>32720844
It'll be inside a gas block, those tend to get pretty warm. From what (little) I understand of spring metallurgy, doing compression cycles while heating and cooling could be bad for a spring that, if it failed, would bolt-action the rifle.

From my reasoning, I'd rather overkill the spring so that it is not a point of failure within its rated operating life; seeing as how the actual compression distance will be pretty small compared to the size of the spring, failure shouldn't occur from compression cycles.

http://www.springhouston.com/materials/

These guys seem to make springs out of pretty much anything.

Maybe regular McMaster-Carr springs (they have some for high heat environments) would be good enough. Not sure yet, it's why I'm still on the drawing board.

I mean fuck just the drawing board part is a bit of a problem. I ain't got the brain smarts for the 3 or 4 variable differential equation (depending on the exact design) to work out how the shit will move around since it's all fluid mechanics.

>>32721041

I can't remember who made it, but there was in the 80's an adjustable gas system for the AR-15/M-16 that used a spring in the gas block.

It had issues, but the examples I saw were pretty crappy.

I'd guess that a reasonably well done take on the White system, properly buffered and sprung would be fairly useful for when someone was hanging all sorts of cans on the loud end.

I'm guessing that is the direction you're going? (without giving too much away).

>>32720668

Seems like a softer impulse would be a great thing to have on many firearms. Was there any reason besides fouling/requiring grunts to maintain it that caused the gas system to be basically never used again?

Then again, it seems like the same effect could be achieved by putting the piston head more towards the rear and adding expansion room that way.

>>32721187
Kinda, and thanks for the discretion. Basic idea is to have one moving part, one spring, and let physics do the rest (hence why I'm trying to convince my engineer uncle to help me math a bit for a case of beer, but you know how family men with three kids are when they leave work at work). Using good materials and a modicum of attention during manufacturing for some sort of quality control, it could be useful if going between can and loud muzzle often.

For me to want to be happy with it, it would need to survive for at least a bit in an F/A range.

>>32721216
I've heard of people softening up AKs, I think allowing more cushion room before the piston could help some piston designs. Not sure why people don't bother; is it because they think piston-gun shooters don't give a fuck, or is it because it doesn't work well?

>>32721187
Well, now with suppressors gaining popularity again adjustable gas blocks are becoming available now.

>>32721273
>adjustable gas blocks are becoming available now
My idea is more that it would adjust itself. Could be handy, and even compared to an adjustable block, it would be a bit less gassy in an AR because reasons.

>>32721298
Meh. How hard is it to flip a set screw over when you mount your suppressor? The AR-15 gas system is already designed with pressure relief for optimum operation normally.

>>32721333
Well, what if I could sell mine for the same money as your manual one?

My second design (slightly more complex in fluid mechanics, but still simple in manufacturing) would even adjust for less gas, say with super soft handloads in the cold.

So your AR would cycle exactly the same between any ammo and any muzzle device with no adjustments.

>>32721264

I mean, the gas plug was infamous for falling off in the M60, but modern manufacturing materials should be able to correct that.

Might also be a bitch to clean, since causing the gas to slow down and cool could cause it to deposit more residue in the expansion area.

>>32721216
>>32721264

Well, the whole idea of "soft recoil" is not new. Max Atchisson and James Sullivan were working towards that goal. Neither result was very marketable, Sullivan kind of managed to sell his idea as the "Ultimax" LMG, but the whole concept of "give the action room to work and let lightly loaded springs soak up the rest" CAN work.

I've fired a match ported AR with a hydraulic buffer that would deliver zero felt recoil off the shoulder, but would FTE if fired from the hip. It was pretty damned neat.

It's a balancing act, and if you can make it work, and make it work in the AR/M-16 platform, people will listen.

>>32721387
Why bother? FN's M240/249 are superior designs over the M60 anyways.

>>32721422
What about a counter-mass? There's some weird russian AK-thing with a pulley or something (not the AN94). Sure it's more weight in the gun, but it wouldn't have that knife-edge problem found in firearms that try to balance shit out.

>>32721499
All these recoil countering guns don't really work because they're fighting the laws of physics. Every weight pushed opposite the direction of recoil will have to come back, causing recoil in that direction anyways.

>>32721499
>There's some weird russian AK-thing with a pulley or something (not the AN94).
It has a to be the AN-94, no other gun used pulleys in their balanced recoil system (AEK or AK-107)

>>32720857
Rings are necessary on automotive scale engines because of emissions requirements, demand for high compression, and expectations of oil longevity and consumption standards.

Not to make them work.

File: AEK 971.jpg (59KB, 750x387px) Image search: [Google]

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>>32721499
AEK-971

3 goes inside of 2. When 2 recoils back from the piston, 3 goes forward and cancels out some of the momentum of 2 going backwards.

>>32721545
>>32721579
Wait yep you're right, pulley thing was my sleep deprivation talking.

>>32721522
At least it's not a Kriss.

Because having it recoil up and down is better than back-forward, right? What a retarded idea.

>>32721623
I think it's a good idea on their part. It sells on the recoil reduction meme and space gat looks, even though it's nothing special. Doesn't get much better than that if you want low effort profits.

>>32721682
Good marketing idea, I guess yeah.

But as a gun, it makes me feel bad for the poor thing's machine spirit. I just see one and think it's screaming "kill me, it hurts to live".

It's useful to see who's dumb by looking for people who think it's a good idea to buy a kriss (for "performance"). For looks/fun range toy, sure I guess, whatever floats your boat.

>>32721493

Considering the Piggie was basically a sheet-metal Lewis gun with a White gas system and a bastardized Browning 1917 feed, I was amazed they worked as well as they did.

Still, if the NFA ever vanished, I'd own a M60D, just because.

>>32721556

If you want them to work reliably over a long period of time, and be cheap enough to be economical, you do want rings.

Machining a piston and crankcase to tolerances sufficient to form a gas seal is madness if you are making more than a handful.

>>32721784
>Machining a piston and crankcase to tolerances sufficient to form a gas seal is madness if you are making more than a handful.

Again, stop thinking automotive.
Loads of "piston/cylinder" combos do not use rings of any form to seal.

Most of the "can" or "sealed" fridge compressors I used to use as air pumps for spraying paint, did not have rings, for example.

>>32721872
Big difference between a clean low pressure system and hot, dirty, high pressure.

>>32721938

Scroll back, note the cutaway engine I posted.

And "clean"? AC compressors are forced to deal with oil and whatever crap someone decided to feed them as media, be it R-12 , ammonia or propane. In addition, the duty cycle of an AC compressor makes what most do to a car seem tame. Like "start from full load at WFO and hold till suddenly shut off" Not condusive to long life.


All that aside, maybe you'll look at some early AR pistons,and note that many did not have rings.
There are some fine images in "the Black Rifle" illustrating this.

>>32721872

Oh no, I'm a different anon, but the guy I responded to is this guy.

>>32721556

who said

> Rings are necessary on automotive scale engines because of emissions requirements, demand for high compression, and expectations of oil longevity and consumption standards. Not to make them work.

And that was explicitly about automotive.

The argument in this thread reminds me a lot of engineering school. A classmate went all-out designing his fixture by the book, and included a lot of things that the book told you to have, and essentially made a mini-automotive transmission at great cost. Then the professor pointed out he was dealing with about 5 foot-pounds of torque, and his expensive transmission could have been replaced by a piece of plastic tubing between the motor and the load.

You don't need everything all the time, but you need it when you need it.

>>32722557
>note the cutaway engine I posted.

Yes, it's a toy engine.

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>>32717184

DI is a pretty bad explanation. Mechanically speaking the Stoner gas system can be best described as a gas delayed Colt Ace system. Yes there are obvious differences in extraction and feeding, but the basic concept is the same.

>>32719805
If in another universe, the russians had designed the M-16, you can rest assured there would be no rings in it.

Is "carrier tilt" a meme?

>>32726382
Not for guns with off axis driving forces.

>>32718028
Patents?

>>32717873
>>32717938
sticking a longstroke in an AR (without modifying a handful of other parts) doesn't work well, do your research. On a MAS it probably works due to the fact the bolt rides on rails, unlike the AR's 'Hotdog down a cylindrical hallway' action

>>32724704
A cutaway of a functioning two stroke engine, but I'm sure you'll now go on about "lol model airplane engine", or some similar nonsense, utterly ignoring the point of my and other's statements..
>>32726661
I never mentioned mounting any form of overbore piston to the AR-15/AR-10, not sure where you're going with this. The piston in the AR-15 is rather, concentric to the bore.

>>32726742
>everyone I argue with is 1 person
Oh you're one of those morons.

Why can't you admit that you said something stupid about a field you clearly don't know anything about?

>>32725883
Isn't that 22 conversion for a 1911?

>>32720425
I'm sure it's no more an issue than in any short-stroke gas piston design.

If you're applying the force off-axis, then don't use a cylindrical bolt in a tube. Put some fucking rails in for the bolt to slide on. Mission accomplished.

>>32728050
But wouldn't it be a simpler and cheaper gun if you ditched the rails and did what I suggest?