Maybe this is a newb question but what exactly was the purpose

>>32795794
Gas blowback has less recoil than DI.

>>32795794
Autistic answer: The AR-15 does use a gas piston, it's just not located over the barrel.

Real answer: Stoner was all about that in-line recoil. Keep all the moving parts in line with the bore axis and shit.

>>32795794
Saves weight, lower costs, and reduces the mass of the operating parts, and thereby the wear on mechanical parts due to movement. By removing the gas piston, the potential amount of moving mass is lowered, thus decreasing the potential for a disrupted sight picture, as caused by the mass of the piston adding to the disruptive mass

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Has the world come to realize over the years that Stoner's system is worse than a gas piston? Sure it has its small benefits but it's also far more difficult and expensive to manufacture, can't use a folding stock, and has to be cleaned more frequently (inb4 "self cleaning" or some shit).

>>32795794

>Maybe this is a newb question but what exactly was the purpose of Direct Impingement?
The biggest advantage of the AR gas system is weight savings.

>Genuinely curious why wasnt the AR designed with a gas piston system?
Then it'd be an AR18.

>Is there some sort of inherent benefit accuracy wise to DI?
No. It does, however,have different recoil characteristics over other systems because of the lack of extra reciprocating, rotating or locking parts.

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>>32795875
Why would a DI system prevent you from using a folding stock?

>>32796063
Size of the buffer system.

I don't think this was intended in the design necessarily and I have no qualitative or quantitative data to support this but I do wonder if the excess gas bleeding out of the ejection port during doesn't help to keep sand/dust out of the chamber. This could be where self-cleaning meme comes from. Just a theory.

>>32796063
It's not DI.

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>>32795794
DI has less reciprocating mass (mass moving back and forth) and its further back in the gun which is more manageable than having it out in front like in a piston system

the big downside to DI is that the gas that pushes the bolt back, enters and can gum up the firing mechanisms, which isn't a problem with piston systems

>>32795875
Generally speaking there are very few DI rifles(whether it's Stoner's design or not) that went anywhere, from top of my head I can think of MAS49 and some Swedish gun which name escapes me right now(AR-10 and 15 too, ofc).

The benefits and drawbacks are obvious at this point so it doesn't even makes sense to rave on about it but generally speaking, it works, it's just a little bit more like this than that

For modern rifles AR-18's short stroke piston seems to be more common idea - HK 416, SCAR, L85A2, G36... all of them use something similar

Now the deal is that the difference is still miniscule

People tend to say - hey, AK has bigger recoil than AR, obviously it's even worse than it in full auto, but they're talking about 7.62x39 rather than 5.45x39. There IS a difference between those and this is in favour of AR but this is very minimal. The difference in case of rifles mentioned earlier and AR are even smaller.
Then the comparison goes to the absolutely surrealistic scenarios. Torture tests, whether mud(which will screw AK) or ammo dump(which will fuck up AR) and other stupid shit. Worthless

In the world where the difference between various military rifles is really miniscule, it's mostly about cost savings now. Rifles aren't that important of a weapon and we know it very well - artillery, airplanes, navy, these are the things that are worth spending money for - rifles have to be there and work and not be behind the curve, if they are minimally worse than the competition it doesn't fucking matter. In this situation you save a lot of time and money you'd spend on rearming and retraining your army which is pretty good idea.

Look at the times when militaries replaced their rifles. It was either because some new thing had to be considered and even this tended to be delayed(Brits and 5.56), they weren't sustainable(FAMAS - no spares and no plant to manufacture those) or was simply shit(M14, and even this was coupled with introduction of new cartridge)

>>32796169
the Ljungmann and its progeny, the Hakim and Rasheed carbine.

>>32796169
ag42 although that technically has a tappet hitting the carrier so it's not quite DI if you're being an autistic.

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>>32796269
my mistake it's just the gas tube. it's been years since I've seen one.

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>>32796316

>>32796169
I like what you say bud. assault rifles and all other small arms really are as advanced as they're ever gonna get short of some new technology like phasers. model x vs. model y really just comes down to fanboyism.

>>32796370
>Born too late for the golden age of smokeless powder gun design
>Born too early for the golden age of energy weapons or whatever
It hurts to live

>>32795794
To make the bolt cycle back.

>>32796777
Born just in time to buy infinite AR15s without anyone being able to do anything about it (unless CA and NY and other gay places)

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>>32795794
>>32796063
>>32796077
>>32796156
>>32795875
Stoner's design is an internal piston. Not DI.

Nothing is stopping you from using a folding stock with Stoner's design. The m16 and it's variants wire designed with that buffer tube system for softer recoil.

Stoner's system is easy to clean, inherently more accurate, simplification of parts since the piston becomes the bolt, and most of all lighter weight.

It's 2017 and this has been discussed to death. What the question should be is AR worth it to you over another gun that uses a normal piston? And most the time the answer is yes.

>>32797941
>I'm a Canadicuck

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>>32797979
>Inherently more accurate
Not enough to make any difference
>Can use a folding stock
The BCG is way too long to contain the spring without the buffer tube.
>Easy to clean
And a piston gun isn't?
>Is the AR better than normal piston guns?
Most of the time the answer is no. See: Every military on earth ditching ARs for superior guns like the HK 416, Scar, and various rip offs of AKs and AR18s.

>>32799523
>The BCG is way too long to contain the spring without the buffer tube.

So move the buffer spring up over and extend the gas key ala LR-300

>Every military on earth ditching ARs

They never had them to begin with.

>>32795794
What happens if your piston gets fucked?
Rifle probably inoperable

What if your gas tube gets fucked?
Can still shoot

>>32795794
The Stoner internal piston is smaller and lighter than a traditional long-stroke, short-stroke, or Tappet piston. The bolt carrier does double duty as a bolt carrier and piston to drive the bolt head out of battery. Weighs less, fewer parts, and not really any more conplicated.

Stoner was also big on the idea of inline recoil. A gas piston's size means that the piston is usually some distance above or below the chamber. Even for Tappet systems, the extra weight of the bolt carrier or operating bar is not in-line with the action, so the recoil force is not fully behind the chamber. Blowback designs don't have to worry about the extra weight and size of a piston, but have other limitations, like being non-adjustable without disassembling the gun. True direct impingement also solved this, but does have the infamous "shits where it eats" issue to some degree, and has been unpopular because of this. Stoner's internal piston sort of combines DI, long-stroke piston, and blowback to produce something small enough to maintain that inline recoil, while keeping the reliability of a piston.

>>32799523
>HK 416
>superior
God, I hate this meme.

>>32799703
>It wins contract for French military after thorough testing, while being more expensive than M16/M4
>Not superior
God, I hate this meme.

>>32795794
very light, very simple, mitigates recoil very well

>>32799890
>implying the frog gubment didnt fall for the meme

>>32799890

>It wins contract for French military after thorough testing

M4 didn't enter, only the full length C7. The actual manufacturers for the M4 is FN and they entered the SCAR.

>while being more expensive than M16/M4

That's not entirely true. When taking into account the discount for bulk orders it was most likely cost competitive.

>>32800036
>Only the full length C7
I wonder what that's a copy of...

>>32800059

An AR. So what. The entire competition heavily favored carbine sized weapons making the gas system irrelevant.

>>32799890

The 416 also lost to that LMT AR in new zealand.

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>>32795794
I'd just like to interject for a moment. What you’re referring to as direct impingement, is in fact the Stoner gas system, or as I’ve recently taken to calling it, true expanding gas system. The Stoner gas system is not an direct impingement system unto itself, but rather another free component of a fully functioning gas operated system made useful by the bolt carrier expansion chamber, bolt and gas rings comprising a full gas system as defined by CIP.
Many firearm users run a modified version of the Stoner gas system, without realizing it. Through a peculiar turn of events, the version of the true expanding gas system which is widely used today is often called “direct impingement”, and many of its users are not aware that it is basically the true expanding gas system system, developed by Eugene Stoner. There really is a direct impingment, and other guns are using it, but it is just a part of the system those guns use.
The gas system: the part in the system that allocates the rifle's gas to the bolt carrier group. The gas system is an essential part of a firearm, but useless by itself; it can only function in the context of a complete firearm design. Direct impingement is normally used in combination with direct action on the gas key: the whole Stoner gas system is basically the expansion chamber with direct impingment added, or the true expanding gas system. All the so-called “direct impingment” firearms are really combinations of the true expanding gas system.

>>32802220
delicious pasta, my friend!

>>32802220
Amazing how well this fits.

>>32799452
See:
>...and other gay places

>>32800036
>only the full length C7
No way. Colt Canada has done a ton of R&D and has supplied a ton of great designs. That would be utterly retarded.

>>32804815

Unfortunately, it's true. They sent in the C7, not sure of what revision, to the French instead of the C8. Moreover with FN trying to push the SCAR it's highly unlikely that they'll produce M4s for other countries anytime soon.