Gas piston AR vs Direct Impingement AR

>>32150962

>>>/out/

>>32150982
Is this not a relevant question for /k/?

>>32150962
It's a needless expense that does not reasonably increase performance. Proper firearm cleaning should be done regardless.

>>32151482
Thanks, I was just curious because gas piston ARs seem to be the new tacticool thing.

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>>32150962
1: Piston pros: Mall ninja cred for costing more and doing nothing, reduces carbon in action by about 10% (the other 90% comes out the ejection port like every other gun including DI ARs)
Piston cons: Costs more, weighs more, less accurate because the piston flexes the barrel downwards with every shot, receiver extension gets battered by off-center bolt carrier pic related
DI pros: Lighter than piston, more accurate because barrel remains truly free floated, less expensive, potentially more reliable
DI cons: Accumulates about 10% more carbon from the gas tube (does not make a practical difference), not nearly as much mall ninja street cred for spending money on gimmicks, potential to melt the gas tube with ridiculously, impractically, impossibly long strings of full automatic fire (700+ rounds nonstop)
2: Highly subjective, but POF, LWRC and H&K for piston, BCM, Colt, Aero for DI, though most everyone makes decent quality GI parts these days. I'd advise against boutique manufacturers like 2A, Noveske, Larue, JJFU, LWRC or Erathr3 simply because they are charging more for looks, not function. Some companies like LMT, Daniel Defense, Knight's Armament and GA Precision actually make high quality ARs that are worth the increased cost
3: Google yourself, but can't go wrong with Colt, BCM, FN, Smith & Wesson, Sig, Windham, Aero or Bushmaster
4: DI for certain. Cheaper, less wear on parts, more accuracy potential

Piston ARs exist solely for variety. They have no benefits to speak of and have many flaws which some manufacturers have been able to partially mitigate (H&K and POF did best at reducing receiver extension wear), but the flaws inherent in the system make piston inferior to direct impingement if they cost the same. The fact that piston costs more and is worse means the only people you see with piston ARs are mall ninjas. And yes, SEALs are the ultimate mall ninjas who have to have the latest gimmick-of-the-week which is why they used HK416s.

>>32151904
Thanks for the awesome reply, man. Piston is way out of budget but I wanted to see if the mall ninjas had any real advantage over us. Definitely leaning towards DI AR.

>>32151904
>less wear on parts
>DI
pick one

save your money go DI

>>32152023
Do you know why piston guns cost more? Is it just a company thing or is manufacturing a piston really that more expensive than a gas tube?

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>>32150962
Piston is better and if you think im not right you are a fucking retard

>>32152060
Any specific reasons why they are worth the extra cost?

>>32152056
scale, tooling, and design costs are expensive
millions of di guns exist with a fuckload of different companies producing them and competing.
meanwhile if you want a scar you can only get it from fn and they set the price.

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>>32151980
You will see two main selling points with piston ARs: "cleaner" and "less heat," both of which are complete marketing bullshit.

The majority of carbon is from smoke trailing spent cartridges out of the ejection port. The gas coming through the gas tube is ejected out the side of the bolt carrier, pic related. There is only a very small amount of leakage where the gas tube fits into the gas key. That small bit of leakage is the only difference in carbon between DI and piston.

As for heat, a lot of manufacturers claim that piston doesn't heat the handguard, but once the piston is activated it vents gas under the handguard.

>>32151994
There is far more mechanical wear in a piston setup than DI, especially the bolt lugs, receiver extension, piston and piston cup. DI does not wear in those areas at all.

I'll explain further:
In a DI AR, gas comes back through the gas tube, enters the bolt carrier, gas pushes the carrier back, which cams the bolt, unlocks the lugs and allows the whole bolt carrier to come out of battery. All the force is being imparted in the center of the bolt carrier, in line with the barrel. There is little wear because the bolt is not rotating under pressure and because all the forces are centered on the bore-line.

In a piston AR, gas enters the piston cup, impinges the piston, the piston then pushes back on the bolt carrier from the top (not the center), this tilts the rear of the carrier down, wearing the receiver extension. The force yanks back on the bolt, but the bolt lugs are still engaged under this tension and can't come out of battery, so the bolt carrier is the only thing that can move. The carrier moves back, this cams the bolt, whose lugs are still being tugged against the barrel extension, the bolt rotates under this pressure, grinding against the barrel extension, and unlocks. This causes wear on the bolt lugs, the carrier tilts down because of the uneven pressure imparted at the top, and more wear is achieved.

>>32152143
OP here. What you said goes with what I've looked into on the matter so far. Piston guns are slightly cleaner but DI is more accurate. How badly does a piston fuck up the accuracy?

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>>32152191
Not that much. Where you might expect 1.5-2 MOA with bulk ammo from a DI, you might expect 2-2.5 MOA with piston. With quality match loads, maybe 1 MOA with DI and 1.5 MOA with piston.

But it's not a hard rule. I had a $3,000 self build DI .308 AR which I could not get to do better than ~1.3 MOA after pouring money into it, but this $900 Adams Arms piston .308 does ~1.1 MOA with Gold Medal Match factory ammo.

>>32152232
Go figure, right? I know H&K is selling a neutered version of the HK416, the mr556a1, for $3200. Thing doesn't even have a chrome lined barrel. I'll have to look at those companies you suggested like Daniel defense, knight's armament, etc. before setting a budget for myself. Thanks for all the useful advice, any advice is appreciated.

>>32150962
>First AR

DI. They are cheaper, reliable if you keep them anywhere near clean, have lesser recoil impulse, slightly lighter, universal, etc. 20 inch guns in general have better reliability, mostly due to gas tube length IIRC. (longer barrel allows for longer gas tube which allows for cooler gas to hit the blot) That said, most AR's these days are M4geries and they've pretty much worked out all the kinks. Any big name manufacturer will do, but if it's your first AR I suggest getting a Ruger or S&W. Set aside $1000 for the gun, mags, ammo, and cleaning supplies if you don't have any. Save for a scope if desired. If you want to go a bit cheaper get a complete lower and buy an upper, or if you want to be more hands-on/1000% Jewish get everything stripped and assemble it yourself.

Piston AR's are mostly a meme, but they are apparently easier to suppress. Other than that they have no significant advantage.

>>32152341
I don't think I'll be throwing a suppressor on an AR, considering that I'm not in need of stealth killing insurgents. Could have for mall ninja value though. Also, kek. "1000% Jewish"

Piston is superior because it can suppress easier, this is a huge ass fucking advantage.

The weight is only a little ounce more.

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>>32152323
If you actually wanted to look into piston despite everything I've said, my opinion is that POF has the most polished, least destructive piston system currently available. And it's not HK expensive either.

But the kind of DI AR you could build with piston money would be comparatively nicer.

Let me also clarify that the difference in accuracy is in potential, not practical accuracy. DI does not wear like piston does, components don't change shape (piston cup), get bent (piston rod), wear (receiver extensions), grind (bolt lugs), or peen (piston key, pic related). Because of those inherent mechanical problems, piston has more opportunity to be inconsistent, and consistency is the key to accuracy. DI has less opportunity to be inconsistent because it doesn't beat itself to death, that's what makes it potentially more accurate.

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>>32152411
False and ridiculous.

Post your suppressed AR and restate your opinion.

>>32152411
Don't you need some special, bullshit license to utilize suppressors? Also, I live in libtard Illinois so anything gun related is a pain in the ass if it requires state authorization or whatever.

DI like other have said it is cheap gas tube and gas block... that will run you any where from 50 to 100-ish bucks.

As where the piston system by it self is round 300 or so. Also you got to ask yourself if shit hits the fan and something breaks where are you going to find spare parts for it.

>>32152433
It's federally licensed, yes, you have to spend $200 tax.

>>32152447
>It's federally licensed
While this is an option for business purposes, an individual does not need a license of any sort.

You only have to buy a tax stamp, fill out the appropriate paperwork and wait a year.

>>32152459
Still a very long process.

Still, a suppressed piston AR at home is good for home invasion.

>>32152446
Not gonna be a problem when the US military switches to piston AR.

>>32152481
What you meant to say was "Oh I was mistaken, got it."

>>32152497
OK brah.

>>32152446
You're right in that sense, there's a million DI guns out there and not as many piston ones.
>>32152414
I prefer accuracy over reliability, to a reasonable sense. I think as long as I keep my gun clean, I shouldn't have any problems with reliability. As you said, DI has more potential accuracy and I can work with that.
>>32152459
You think a poorfag like me is going to spend $200 to wait a year for a suppressor while scraping money to buy their first AR? No thank you, but good to know for the future

>>32152481
Maybe in the future when I have the money to become an HK über human.

>>32150962
I'm about to buy the Sig 516. Ten years of cleaning an m4 for some faggot to put a white qtip in the chamber right after firing and not being able to go home until the thing is spotless has turned me off of impingement completely.

It's like they drilled a minor case of ocd into me and I hate firing my ar after I've cleaned it even though I know I don't have to clean to that level anymore.

The simple fact of no carbon build up on my carrier group is enough to buy piston for me. It's ultimately up to you and a lot of poor people that can't afford a piston rifle will cry saying you're a faggot because there's nothing wrong with impingement and you're trying to hard to be tacticool while they have 18 bipods, rails, and flashlights all over their ar. Whatever man, buy what makes you happy.

If you can afford it LWRC IC or Gen 2 Sig 516. If not and you jyst wasn't to test the waters Adams arms makes a few budget ones. Personally I would buy an ar platform built specifically for the piston, example the lwrc or 516, I wouldn't buy the conversion kits.

>>32152537
Dude, that sucks man. But since I'm just starting out with my own guns, I'll probably go DI. Would be nice to have a piston in the future for variety though.

>>32152537
Before you go spending money how about you find some proof that piston ARs are cleaner than DI ARs? Not anecdotal evidence you read on a forum promoting products.

When you find some proof, post it here.

Don't be surprised if the thread 404s before you're able to.

>>32152536
Dude, they have drop in piston kit nowadays.

https://www.youtube.com/watch?v=GwyQZLs2Yvs

Just buy your DI and drop that shit in.

>>32152537
You should see one of Frank Proctor's M4s.
http://soldiersystems.net/2015/05/09/gunfighter-moment-frank-proctor-14/

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>>32152592
Whoops, in my rush I forgot to attach the JPEG

>>32152553
Carrier tilt is a thing. Don't bother.

>>32152622
A non fucking issue.

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>>32152634
>product a destroys itself
>product b does not
>buy product a
ok

filthy 14

>>32152658
You know full well carrier tilt is a fucking meme and there have been two militaries who switch to using piston AR already, not to mention the muhreen corp using it as a SAW.

>>32152690
A rifle built from the ground up to be a Piston AR.

>>32152696
Actually 416 was plagued with carrier tilt too.

But it was fixed.

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>>32152690
this is literally evidence to the contrary of your statement

adding rails and bevels only helps, it does not fix

>>32152709
Well shit.

>>32152711
Oh please, explain how the corps still use their 6500 M27 then.

It's a long ass time with a lot of ammo count.

>>32151081
There are no "pros" to a gas piston AR.

If you want a gas piston rifle, buy one designed to be a gas piston rifle.

If you want an AR, get a DI AR.

But anyway:
>gas piston pros:
Nothing
>gas piston cons:
weighs more
less reliable
recoils more
eats your buffer tube
costs more
suppresses worse
limits handguard options
less accurate

>DI pros
More accurate
weighs less
more reliable
less recoil
doesn't eat your buffer tube
extensive handguard options
triggers pistonfags
costs less

>>32152696
There are lots of those which exist. One is called an AR180.

Taking an AR15 and retrofitting all manner of gimmickery to turn it into something it was never intended to be is stupid.

>>32152731
Because... this will be hard to believe...

They replace parts constantly. They are military, with manufacturer contracts and armorers.

>>32152738
This. If you want a piston, buy a gun that was designed as a piston driven gun.

>>32152741
>They replace parts constantly. They are military, with manufacturer contracts and armorers.
You are talking about the corps, the poorest mainstream branch.

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>>32150962
All piston ars have carrier tilt, even the H&K MR556/762

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>>32150962
1.) DI has fewer parts, inherently better accuracy, smoother operation due to symmetrical in-line forces, and the only real downside is additional heat in the receiver and needing a tool to efficiently and quickly clean the bolt. In my view, piston is flatly inferior.
2.) If you want a piston gun, I would go for LWRCi above all else...
3.) An LWRCi will run you $2500-3500
4.) DI, no questions asked.
Get a BCM upper and build your own lower.

>>32152741
>Taking an AR15 and retrofitting all manner of gimmickery to turn it into something it was never intended to be is stupid.
the AR15 built in the 60s is different than the AR15 now.

The only thing that stays the same is the gas system, and now that changes too via piston.

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if you want a piston gun in 5.56 get a mini 14 or scar. a piston AR-15 is basically an AR-18 and those are unicorns. plus dgi is a neat system in my opnion

>>32152738
What is this about piston suppressing worse than DI?

>>32152411
>piston is superior because it can suppress easier
BULLSHIT.
>hey let me just vent these high-pressure gases directly out of the barrel directly behind the suppressor, surely that won't make a crapload of noise!
Unless you have an adjustable gas block and completely close it so it's a straight-pull bolt action (which can also be done on a DI gun), it's going to be significantly louder. Like, 7-8dB (70-80x) louder.

>>32152774
A piston gun vents high-pressure gases from the barrel directly to the exterior of the gun.

High-pressure gases are loud. Kind of the whole operating principle behind suppressors: Contain them until they're no longer high pressure, then dissipate them gradually at low pressure.

A DI gun routes them back through the receiver along a relatively wide and long channel, allowing them to cool and depressurize (port pressure). It's quieter with a suppressor, by a large margin.

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Not one mention of pws


Shame on you guys

>>32152776
Actually it's not bullshit you scrub nigger

>>32152816
Literally the laws of physics says otherwise you retard.

>>32152816
Which do you think is going to be louder--gas leaving the gun at 60,000PSI, or gas leaving the gun at 14,000PSI?

Because in a piston 5.56 AR, gas leaves the gun at 60,000PSI. Because it comes straight out of the barrel.

>>32152836
It's coming out at 60,000 psi in every flavor of piston ar?

>>32152855
Yep.

Because it takes a very short route out of the barrel. As in, there's a hole in the barrel with nothing over it.

>>32152776
>>32152788
It's not a matter of sound, it's a question of reliability.

DI guns are dirtier than piston guns due to the nature of gas blowing back to the guns.

>>32152891
Lies of a cuckold.

>>32152907
Good joke.

You cucks would go "lol piston AR is better anyway" when the US adopts the HK 416 anyway.

So, you want an AR

Buy a DI the way God and Stoner intended.

Want a piston gun? Buy a Tavor if you want to shoot a 223/556 round or a good AK (arsenal) if you want a 762.

Piston ARs are a solution looking for a problem. All other things being equal a piston AR is heavier and less accurate than an identically spec'd DI

DI is simpler, lighter weight. You don't need a 3000 dollar rifle, you need a 1000 dollar rifle and two grand in ammo.

As to what rifle to buy

Since you're brand new Windham Weaponry if you want to get the cheapest good rifle. Lifetime warranty, good QC. NOT mil spec.

Want a rifle you can go to war with for not much more money? Buy a BCM lower at a LGS, if you do your homework you can find them under 300. Buy a BCM upper from them direct. Saves money because the 10% federal excise tax only applies to 'complete firearms' only the lower counts. If you buy a complete AR it's charged on the whole thing. Buy them separately from the same manufacturer. It's also cheaper because you can get sale prices

I have a BCM with 20" upper with full rifle length gas system, A2 sight, mil spec, HPT and MPC proofed barrel and BCG, their enhanced trigger group for just over 900 when anything close to that was going for 13-1400 online.

Fit and finish is phenomenal and I'm getting about 1.5MOA w/ 55 gr 223 federal and about 1.3 MOA w/ 62 gr. green tip A huge part of that is how good the trigger is from BCM. Holy cow, best out of the box AR trigger out there.

could probably get her down to 1moa w/ handloads Gonna try out some 77 gr black hills match next week

Bottom line, I've shot the shit out of it and it's never failed. Not once. Modern AR's are caveman reliable. Keep them lubed and clean them when you're done. Nuff said

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>>32152741
>They replace parts constantly. They are military, with manufacturer contracts and armorers

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>People calling DI guns poorfags
How can you say that when there are DI rifles for over $3000 like LWT DI rifles.

>>32152891
>>32152921
Except that's wrong, blowback happens on EVERY gun, piston or DI. The gas comes out of the chamber, not the gas tube.

Gas tube gas is vented out the side of the bolt carrier.

go back to
>>>/asp/
>>>/toy/

>>32155540
On the AR15 there is additional blowback from the gas tube. The piston on the bolt, the inside of the carrier, and the firing pin all get coated with carbon and powder residue.

>>32156352
>the inside of the carrier, and the firing pin all get coated with carbon and powder residue
Which is all scraped off every time the gun is fired.

The only place where additional carbon can enter the receiver is from a poor fit between the gas tube and gas key, and this is a tiny amount of leakage, not a huge, dirty cloud like pistonfags portray.

The difference is tiny. Even suppressed.

Look at the gif.
>>32152143
Where's the gas coming from? It's coming straight backwards out of the chamber. Not down from the gas key. The exact same as happens with a piston.

>>32156671
It's not huge in small cycles but over a long period of time it can absolutely become quite a bit of carbon. It doesn't affect function but it's absolutely disgusting.

>>32156764
>It doesn't affect function
You're human after all.

>>32156804
You're a big guy.

>>32150962
If Eugene Stoner had thought it'd be a good idea to add a piston, he would have. But he didn't, because ARs work best as DI.

people want the superior gas piston system, but don't want to move from the AR platform which can't handle it. So they end up with a half assed compromise.

>>32152060

Stellar argument. I was about to cite evidence to the contrary, but you sure showed me.

As a system I think Pistons are superior, but in an AR I just don't see the point of owning one, that's why I didn't get the mr556 and got my sr-15 (plus some minor dislikes)
I really am in love with the g36/scar/CZ systems and I've been considering picking up a scar

>>32150962
If you want a piston gun go with one that was made to be a piston gun in the first place.

A AR-15 is meant to be a DI gun.

>>32151980
>us
>doesn't own the gun
You probably talk like that about your favorite football team too.

>>32152086
They're not. Get a gun designed to be a piston gun like an AK or get a gun designed to be di

>>32157019
>fighting cancer with more cancer
wow you sure showed him how much brain you are

>>32152788
K, even I know this is horsecrap.
DI suppresses far worse than piston due to backpressure, and most AR's not having an adjustable gas block. The piston is going to be a little less nasty to begin with, and since most piston guns have a regulator to adjust for running suppressed, you actually have a method to keep your rifle from being overgassed and crapping it's gas in your face.

I'm not going to argue with you on any other points, and frankly the AR15 isn't my rifle of choice so idgaf, but don't say something that's verifiably false b/c you dislike piston AR's.

>>32152776
7-8dB is not 80x louder
10dB ~ twice as loud

>>32157994
>DI suppresses far worse
Utterly false.

Gas coming through the gas tube to operate the action does not affect backpressure inside the barrel differently between DI and piston. With a suppressor attached, both DI and piston have increased backpressure, which means increased gas coming back through the BARREL, not the gas tube. It also means higher bolt velocity, which makes piston component wear worse.

The difference comes in where most piston systems have multi-position adjustable gas blocks, and most DI rifles do not. Put an adjustable gas block on a DI rifle and there is no difference between the systems suppressed or unsuppressed.

What that guy said about hot supersonic gas venting from the gas port of a piston is correct though, that bypass makes suppressed pistons louder on the receiving end, despite MAC's measuring video showing it quieter on the shooter's end.

Any DI rifle that fires 7.62 NATO?

>>32158055
Well you're both wrong.

3dB is twice as loud, 10 dB is 14.99 times as loud.

7-8 dB is 5.33 - 6.66 times louder. That's an incredible difference.

What a stupid logarithm.

>>32158126
Literally any AR10/SR25/AR308.

>>32158126
Lewis machine and tool make DI 7.62 guns.

>>32152560
I've shot each. My cousin has the 516 I have a DDM4V9. the 516 runs way cleaner. I'm talking 1000 rounds and still don't even need to clean it.

>>32152622
Lwrc, adams, and Sig fixed that years ago.

Tilt happens with the conversion kits.

Piston is better for:

1. Use with suppressors
2. Barrels shorter than 14.5"
3. Shooting full auto
4. Better shooting with wide-variety of ammo

Pistons are heavier due to the weight of the piston rod itself. Carrier tilt used to be an issue with piston conversion kits, but almost all dedicated piston guns have fixed the issue. The biggest issue with piston guns in my opinion is that there is no standard piston. Every manufacturer has their own proprietary system (and not all piston systems are equal). Most of the hate that pistons get are from people who haven't handled a well-made piston rifle or who feel that their weapon is inadequate (and therefore lash out at the newest kid on the block, like people with small penises). I also do not believe that piston systems are inherently less accurate than DI systems due to the fact that the HK417 beat out KAC in the CSASS competition.

DI is just fine for 99% of shooters and will serve OP just fine. Also, OP is a fucking moron for asking the retards on this board about this.

>>32150962
Figure I'll contribute my .02 since I own both types and I see a lot of bullshit being spouted by people who don't know what they are talking about.

I have an Adams Arms rifle and two DI ARs that I built myself. Here's my observations:

1) piston is MUCH cleaner in the receiver and on the bolt. I have found the piston system to be much simpler to maintain.

2) weight difference is negligible, a few ounces at most. If that much of a difference is a concern to you; hit the weights, bitch.

3) piston has more parts wear. Without having the gas pressure in the BCG to unlock the bolt as in DI, the piston rod slams into the BCG which puts strain on the bolt and wears the receiver where the cam pin rides. You can find pictures of this. I asked Adams Arms about it, they said it was cam pin "tracking" and normal for the system, still wasn't happy about it.

4) piston systems are proprietary. If something breaks, you MUST get the specific part for your system. DI parts are much easier to come by and cheaper.

5) DI less complicated mechanically.

6) Accuracy is not much different between the two, but DI is a little better.

My opinion from experience with both is that DI is the better option. Simply because of DI simplicity, price, parts availability, and less mechanical wear from use.

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>>32151904
>SEALs are the ultimate mall ninjas who have to have the latest gimmick-of-the-week

finally someone on /k/ who has something halfway intelligent to say.

>>32157454
>>32152060

Samefag as fuck

>>32159180
>HK417 beat out KAC in the CSASS competition.
Hk makes better quality barrels. A direct impingment of the same rifle would have better moa