Piston AR15 system VS. Direct Impingement AR15 system.

[eldbillbo]

But extra points for SHTF Scenario,
Let the debate begin!

well in a SHTF scenario if you break or loose a piston part your up the SHTF creek without a paddle. you may wait to see which one the military decides on

Adcor bear is now being considered by the US military and colt just came out with a piston AR ar well, so you may stick with a DI until the smoke clears and see if a standardized system comes out of all this.
a piston system will cost more ,be heavier, maybe even a little less accurate but run cleaner and cooler , cleaner usually means more reliable if your lazy or don't properly know how to properly maintain your DI system in other words clean and lube it.

 

[556]

i guess the clean chamber on a piston gun is worth the risk of not finding parts but again it's $125 for all the piston parts i need so i bought a spare kit.
in a shtf senerio you may not be able to stop and clean and lube your DI rifle which will now begin to jam on you due to carbon fouling like it did in vietnam.and lets not forget your bottle of lube will run out quickly so my oil free piston ar will keep right on shooting dry.
bottom line is there is enough pro's and con's of both rifles that preperation is the key
piston gun.....keep and extra op rod,piston and plug.$125 everything else is interchangable except the carrier key.
DI gun.....keep $125 worth of oil and patches with you and make time to stop and clean it every 300 rounds.
I would carry either of them but when shtf i will grab my piston ar and its parts kit.

 

[mr45auto]

i guess the clean chamber on a piston gun is worth the risk of not finding parts but again it's $125 for all the piston parts i need so i bought a spare kit.
in a shtf senerio you may not be able to stop and clean and lube your DI rifle which will now begin to jam on you due to carbon fouling like it did in vietnam.and lets not forget your bottle of lube will run out quickly so my oil free piston ar will keep right on shooting dry.
bottom line is there is enough pro's and con's of both rifles that preperation is the key
piston gun.....keep and extra op rod,piston and plug.$125 everything else is interchangable except the carrier key.
DI gun.....keep $125 worth of oil and patches with you and make time to stop and clean it every 300 rounds.
I would carry either of them but when shtf i will grab my piston ar and its parts kit.

Uhh, no.

The AR platform has come a long ways since the early days of viet nam.

If you have to stop and clean it every 300 rounds you need a new rifle because yours is a POS. Also who in the heck carries multiples of 300 rounds on them? If your rifle reliably cycles a couple of combat loads ( 4-500 ) rounds without cleaning it is going to last longer than you will. If it's a SHTF you're not going to be shooting hundreds of rounds. Seriously, some people watch too much tv.

 

[556]

Uhh, no.

The AR platform has come a long ways since the early days of viet nam.

If you have to stop and clean it every 300 rounds you need a new rifle because yours is a POS. Also who in the heck carries multiples of 300 rounds on them? If your rifle reliably cycles a couple of combat loads ( 4-500 ) rounds without cleaning it is going to last longer than you will. If it's a SHTF you're not going to be shooting hundreds of rounds. Seriously, some people watch too much tv.

ok,you win....i can see your that kind of guy that has to be right and there is no other gun out there other than what you have.
i have both,i love both but the piston is a better gun hands down and im the guy who shoots 300 rounds at a time.
300 rounds with my noveske DI....fouled and needs oiled i dont think it's a pos by any means
my pof piston is clean and needs no oil after 300 rounds so you tell me which is better?both are sub moa.

 

[Hardwood floor guy]

Uhh, no.

The AR platform has come a long ways since the early days of viet nam.

If you have to stop and clean it every 300 rounds you need a new rifle because yours is a POS. Also who in the heck carries multiples of 300 rounds on them? If your rifle reliably cycles a couple of combat loads ( 4-500 ) rounds without cleaning it is going to last longer than you will. If it's a SHTF you're not going to be shooting hundreds of rounds. Seriously, some people watch too much tv.

this guy is clueless 556,dont waste you time talking to a brickwall.

 

[.40cal EMT]

Tag for later info, and well I'm still deciding if. Sig Sg556, or a DIY DI build is a better option, and my DI gun always looks filthy after a day out in the woods, and I've scrubbed even using am electric toothbrush, and even as far as dipping parts in brake cleaner after some filthy ammo I was shooting up from a friend

 

[mr45auto]

this guy is clueless 556,dont waste you time talking to a brickwall.

I wont even waste my time but needless to say I've been running the platform since before many on here were born.

 

[Bob D]

I wont even waste my time but needless to say I've been running the platform since before many on here were born.

Maybe that's why you're resistant to the potential improvement that comes with modern innovation.

 

[ArBrnSnpr]

I just built my first AR with a PWS piston upper, and a Mega Arms lower. I LOVE the way the PWS has such a flat/soft push compared to the DI M4's recoil I've experienced (10 years in the Infantry). As far as some of the comments regarding a .223/5.56 not being a sufficient man-stopper and a .308/7.62 NATO being more effective - you're using the wrong ammo! Granted a 7.62 will put someone on their back more reliably than a 5.56, but with the ammo choices available today when the M4/AR15 is used (in it's correct roll) it does it's job just fine.
I carried an M14 EBR as my primary weapon system while on a deployment and I can easily say that within close confines (read 50 yards and closer) a 7.62 doesn't have THAT much greater effect than a 5.56 and weights considerably more, while carrying less rounds and having a greater likelyhood of over pentration (less of a concern in Fallujah than Portland obviously). Not to take this too far off topic from the tired debate of piston VS DI, but since caliber was brought up...

I personally find that the reduced parts compatability is a small trade off for the decreased need for service. Also with a quality piston upper like the PWS, weight is not a concern over a DI upper, and if it is, take your sissy *** to the gym and be thankful you never had to hump a 240B!

On behalf of the DI system thought, I will say that if you're only getting a combat load worth of shooting before you start experiencing malfunctions, there's likely a pre-existing issue with either the mags, or the springs in the gun. I've had range days when I was active duty where 1000 rounds had gone down range before lunch, and I wasn't having to correct malfunctions left and right.

At the end of the day though, I simply enjoy wiping my bolt down and cleaning my barrel after those same 1000 rounds with my piston gun, rather than doing an entire level 3 cleaning like I would with a DI gun!

And as far as parts compatability being an issue with a piston gun - just remember "two is one, one is none." If something is prone to breakage, or there is a known weak link in your system, have that extra component on hand rather than expecting to be able to scavange it when SHTF.

BUT as was said before - get out and shoot both, experience will help you draw the best conclusions!

 

[Bob D]

I personally find that the reduced parts compatability is a small trade off for the decreased need for service. Also with a quality piston upper like the PWS, weight is not a concern over a DI upper, and if it is, take your sissy *** to the gym and be thankful you never had to hump a 240B!

+1 for not lugging a Bravo around! ("Somebody else grab some ammo for this thing, would ya? I'm tapped out!") The weight difference between piston and gas tube is measured in ounces, not pounds. Add two push-ups to your workout once a week, and I think that ought to take care of it.

 

[wichaka]

I usually don't jump on the bandwagon with anyone so clearly...but mr45auto has some valid points.

I must say, those who know the platform can attest that it has come a looong way since Vietnam.
If anyone is trying to compare a Vietnam era AR to today's offerings, is probably still driving a '64 Rambler too.

I will say again, the AR with its current gas system will push the crud out long before it will cease to function.
If yours does not, me thinks its time to look under the hood and see what the problem is. If your AR can't go thru
500+ rounds without a malfunction, its time to look at the quality of AR you have.


How many here have run a gas system AR thru a few classes, where 500+ rounds have been fired and had their rifle malfunction?
If it has...refer to the above.


And also begs the question, what kind of SHTF scenario is one thinking will happen, where your gun will need to be cleaned or jam within 500 rounds???? How many rounds do you think you'll be able to carry on your person? Whatever the amount you are able to carry, your AR should be able to digest without hesitation. If yours can't, refer to the above paragraph.

The AR likes to be run wet, no doubt about that... and any type of lube will do...and I do mean ANY type of lube. WD-40 will work if need be.
When I go thru an extended class or firing session, I have small bottle of motor oil on hand. In a SHTF scenario, used motor oil will do.


I have no problem going out on a limb about this subject...but there are a lot of pure junk AR's on the market, and they are the ones giving the original gas system a bad name. I doubt very much, that there are very many on this forum, or even in this thread that will ever push an original gas system AR to its limits.


Folks, let's be sensible about the subject. Too much Internut crap being spewed around here.

If you want to go with a piston system, by all means have at it, you won't hear a bad word from me about it. But if you're going to spew information, let's get it correct so all can make a qualified, informed decision on the matter.


Let's all slow down here and put some reality back into motion...wow.

 

[ZA_Survivalist]

So for a shtf scenario I don't think the 5.56 fully gets it done. However it does serve its purpose and its better than having nothing. Honestly DI is the way to go, common and relatively inexpensive replacement parts are bountiful whereas the piston system parts are hard to find and costly, not to mention most.shooters (survivors) will be rocking DI systems, trade and pickups are way more likely. Folks that get over hung up on total and complete sub moa at distances past 250 yards should really be rocking a bolt action with a larger caliber. I am an ak man, but in this instance, my vote is for the DI system. With shtf, you'll need all the commonly available parts and caliber ammo you can get.

 

[doubletap007]

if your piston gun breaks swap the upper for a DI upper,problem solved.
I would choose a piston gun to start with though.

 

[eldbillbo]

I really don't think that some of you piston guys should get some defensive. The OP asked a question and some chimed in with their opinions .
both have their strenths and weaknesses . Mr45auto was just pointing out that there has been a lot of improvements since the first m16s were issued in Vietnam . Keep in mind the Brass cut corners and issued M16s without chrome bores without cleaning kits, and dirty ball ammo as well as faulty mags .

some of the most recent improvements such as special coatings and better mags, proper buffer weight, better springs, chrome lining, ect have made the DI system just about a flawless system but have been over shadowed by the Piston hype .

many of these improvements such as the mags have benefited the piston ARs as they have never had to experience faulty mags which were the #1 cause of failures for the AR15 platform . If you go to the piston forum on ar15.com you will see some experiencing problems with the piston systems . Some related to the piston system themselves and others that are the same as those experienced with DI systems such has mags proper buffer weight and getting not enough gas (Short stroking) or too much gas.

I followed the piston craze from its Resurrection by Kurt at KKF who reintroduced the piston idea since he was my gunsmith and i talked with him often the first 2 piston system to hit the market was based on his design but he did not have the machinery to produce them .

I like the piston system idea . I have a PWS piston system that has become obsolete they no longer make parts for it so if i loose something or it breaks i will have to buy a complete new system now if you have deep pockets thats fine but dumping a $250 system should i lose or break a part is gonna piss me off.

I put over 1000 rds in a day through a DI system without lube or cleaning without failure. i have personally dumped 3 100 rd beta mags and several 30 rd mag of nasty dirty wolf ammo through my friends DI m16 with no failure and no lube or cleaning granted it got dirty internally . i have never had a failure any any rifle i have built or any colt. I have fired thousands of rds through DIs with no failures due to lube or carbon so until i have one take a dump on me i due to those reasons i have no reason to doubt them.

but it all comes down to this to each their own. I am not gonna twist your arm to switch to DI so don't twist mine to go to piston already have one . like them both just pointing out some some pro and cons to owning a piston.

Its kind of funny though how many have tried to make the AK look more like a AR then they got the the bright idea to make the AR act more like a AK

 

[CaliberGeek]

DI or bust for the AR-15. If you want a piston gun, there are other platforms that were designed to be piston rifles. The AR-15 was designed around the fact that it would operate a DI gas system. Although higher-end companies are redesigning the AR-15 completely to properly accept a piston, the prices of these "properly designed" piston AR-15 are ridiculous. And the cheaper piston AR-15 are basically DI guns converted to accept piston, which leads to timing problems and premature failure of the entire rifle.

The AR-15 is not the end-all be-all of the 5.56NATO caliber. There are many many military proven rifles that accept the 5.56 cartridge that run on piston. If you want a true AR-15, my OPINION (you don't have to agree with it, so don't get your butthole all puckered up and chaffed) is to get a DI.

Hopefully no trolls bash on my personal opinions:

 

[eldbillbo]

I recommend keeping a eye on the adcor Bear as it was designed from the ground up addressing all the issues with piston add on designs

Here are some things to keep in mind about the piston now piston guys don't get in a uproar these are just buyer tips.

Carrier tilt is real but for some reason its not as bad in some as it is in others maybe with a true mil spec tube it take longer to ware a grove in it . Sure many will argue that a buffer tube is a replacement part that once there is a grove just get a new one , they are only $45 but a grove will eventually cause failure. but they have come up with many solutions the best being the special buffer made by slash buffers that goes into the back end of this will cost you about $100

the new special carriers have been know to still show tilt issue although it has slowed down the pace. PWS makes a special tube that goes inside the receiver that the tail end of the carrier rest on . its a $90 tube and only certain higher end stocks with locking stocks like the CTR stock will fit it without wobbling . plus pay special attention to instructions while installing it so you don't damage you tube or receiver.


the pounding and the tilt causes stress and ware on your upper receiver also sure many will argue that the upper receiver is a replacement part ( i have read the arguments stating this) the cam pin will ware a grove into the side of the receiver . i had this happen with my last piston system granted it kept working but it was a nasty groove. so replace it with a special cam like the POF roller cam i am sure most of the newer systems are including a special cam pin i think adams also developed one.

some piston kits come with a little spring that goes between the bolt and carrier to aid in unlocking the bolt . maybe it helps to keep the bolt centered as thats what the rings use to help do but in some cases now add resistance to it unlocking

you will have to spend more for a piston system . but they do keep the bolt running cooler if that really even matters. it will keep the bolt carrier group cleaner so you can run that dirty wolf ammo all you want .

Here check out the first piston Ar15

 

[ArBrnSnpr]

Some decent points being made - however I'd have to say the "it was designed that way, so that's the better option" argument is questionable to me. As was said, it is only an opinion, but just to tickle your brain how about this - car/truck brakes were originally designed as a drum system, once the caliper was invented it became the norm and drum brakes are only found on cheap/turd cars these days. Point being, because something was designed a certain way, by no means that is the "best" way it can be. Another example would be the M-16 - it was designed to not be cleaned, and to not have a chrome lined barrel and with inferior springs and magazines. By the argument of "it was designed that way, therefore that's how it should be," AR15/M4/M16 rifles should still be manufacured without chrome lined barrels, and should not be cleaned which we all know is not true.

I agree that there are benefits to both systems, however "it was designed that way" is not one of them.

 

[eldbillbo]

Another example would be the M-16 - it was designed to not be cleaned, and to not have a chrome lined barrel and with inferior springs and magazines. By the argument of "it was designed that way, therefore that's how it should be," AR15/M4/M16 rifles should still be manufacured without chrome lined barrels, and should not be cleaned which we all know is not true..

Actually it was designed to have chrome lined barrels and cleaning kits but they were not shipped with the original rifles sent to Vietnam as a way to cut cost. And they were not designed to shoot the cheap ball ammo that went over with the early rifles again to cut cost . the Stoner design was fine even with the lighter edgewater buffer but dirty ball ammo , no chrome lining, no cleaning kits in a humid conditions was just asking for failure . don't blame the rifle blame the guy who made the decision to do cut corners .


certain brands of GI mags such as cooper were poorly made. and the good mags required a tap to make sure all the follower was not tilted causing a bind because of lack of the later manufactured anti tilt follower. I would guess during testing the mags were loaded without stress of bullets flying over head with proper care to insure each round was loaded correctly
again no relating to the gas system. also i am sure under testing at a range there

there have bee some great points brought up about pistons . I like my piston AR it does not get dirty in the bolt carrier ( the piston gets dirty though). But i also have a DI.

a few months ago i could have got a complete adams kit for $180 . i thought i could sell my DI carrier and glas tube and gas block for $110 so the conversion would so the kit would only cost me $70 but i thought about it like this i have had no problems with my DI so why do it so i passed on it. but thats just me. If you want a piston thats up to you don't let any thing i have to say stop you. but its somethings to consider.

 

[eldbillbo]

I am not saying not to buy a piston system just trying to debunk some of the misconceptions based on early poor performance as well as point out some of the weaknesses of the piston system so that the op can have some basis for basing a decision of what and when to buy,

If the DI Ar15 is so bad why has is survived over 40 years and is the most popular rifle ever made with the biggest firearm industry supporting it.

 

[ArBrnSnpr]

Actually it was designed to have chrome lined barrels and cleaning kits but they were not shipped with the original rifles sent to Vietnam as a way to cut cost. And they were not designed to shoot the cheap ball ammo that went over with the early rifles again to cut cost . the Stoner design was fine even with the lighter edgewater buffer but dirty ball ammo , no chrome lining, no cleaning kits in a humid conditions was just asking for failure . don't blame the rifle blame the guy who made the decision to do cut corners .


certain brands of GI mags such as cooper were poorly made. and the good mags required a tap to make sure all the follower was not tilted causing a bind because of lack of the later manufactured anti tilt follower. I would guess during testing the mags were loaded without stress of bullets flying over head with proper care to insure each round was loaded correctly

Fair enough that the barrel may have been designed to be chrome, but the rifle was still designed with the light weight buffer and poor quality magazines (poor springs and followers) and was issued with ammunition that was not suited for the rifle. Fact still remains, in it's orignal form - there was ample room for improvement which is still the case with all things to include the AR15. We stop progressing as a society when we stop looking for improvement...

Regarding the magazine tapping, that is to ensure that the base off all the rounds was evenly seated against the spine of the magazine so that the bullet would not drag on the leading edge creating friction and either causing the follower to tilt, or causeing a slow feed which would result in a FTF malfunction.

The DOD didn't truely address the anti-tilt follower issue until 2009 with the production of the tan follower. When I was in basic training in 02' the standard issued mag was still issued with the black follower which had a single leg to stabilize the rear of the follower, which was rearely the problem area. A few years later the green follower was issued to address the tilt issue, but failed misserably at correcting the problem. The military than fielded a tan contoured follower that looks exactly like the enhanced Magpul follower and issued the, "If it's TAN, thats the plan, if it's GREEN it'll start to lean, if it's BLACK, send it back" slogan in PMCS manuals.

Improved magazine increases weapons reliability | Article | The United States Army

The rifle has had an inferior magazine for over 50 years in it's designed form, and the fact that improvments are still being made by the military and civilian users just solidifies my point that just because it was designed a certian way, is by no means a sufficient reason to chose one operating system over the other. Use one of the many other options to make your choice and leave the "because it was designed that way" argument where it belongs - with the old magazines, poor quality ammo, and recomendations not to clean it...