differerence between gas and piston AR uppers

[jephs422]

I'm building another upper but up until recently had never seen the piston style uppers. Can I build this style with a regular bare upper and lower, or are the parts specific to the piston type? And is there anywhere I can get schematics or detailed info on them?

 

[Powder_Burns]

Re: differerence between gas and piston AR uppers

Difference is about $300-400 and more parts to wear and fail.
JMHO

 

[jephs422]

Re: differerence between gas and piston AR uppers

Just did a little reading and I'm getting all kinds of mixed reviews....for the price though, I think I'm going to stick with what I know.

 

[Polyak]

Re: differerence between gas and piston AR uppers

The problem with the piston uppers is that there isn't a unified design yet. So you have a bunch of companies with all differing designs, which means all proprietary parts.

Just ask yourself...in 10 years, if a part broke and you didn't have a spare, do you feel confident you could find said part? I don't feel confident with the piston parts, but the standard DI parts should be easy to come by for a long time. That, and I don't really have any issues with DI for which the piston is supposed to fix.

 

[jephs422]

Re: differerence between gas and piston AR uppers

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Stump</div><div class="ubbcode-body"> That, and I don't really have any issues with DI for which the piston is supposed to fix. </div></div>

exactly. I was hoping to read something magical about the Piston system that would make me want it. But it doesn't fix anything that i have an issue with, I just thought it might be cool. But it's definitely not cool enough to build a rifle with proprietary parts.

 

[Rob01]

Re: differerence between gas and piston AR uppers

Piston driven ARs stay alot cleaner in the receiver area as there is no gas/fouling being pushed back there with every shot. I went out with my POF and at the end of the day the bolt/receiver was as clean as it was when the day started, except for the bolt face of course. Much easier to clean than standard ARs.

 

[HTR707]

Re: differerence between gas and piston AR uppers

The only REAL advantage in a piston system is if you shoot suppressed. That is, they stay much cleaner, and less heat is dumped into the receiver. Some claim this makes parts last longer. I have a Colt, with original parts, that is 15 years old and going strong....so.....

They are not necessarily more reliable, though. You do have a little shorter cleaning time. no biggie

There are also issues with carrier tilt on some branded pistons, and this could reduce accuracy. The piston converts the gas energy into mechanical energy and bent op rods are a reality that has to be considered, too.

All in all, even though I shoot suppressed, I still have never seen any great advantage in a piston. I still shoot DI, and my guns are reliable in the high 90's %.....like 99.9.

 

[ubershinobi]

Re: differerence between gas and piston AR uppers

The Direct Inpingement system works just fine. Gas is always tweaked with newer adjustable gas blocks so suppressed can always run at its best. Once a piston system is unified for the ar15 platform there will be too many variables. Not to mention they are less accurate due to the addition of more moving parts and harder to free float the barrel.

 

[sobrbiker883]

Re: differerence between gas and piston AR uppers

Part of the Stoner rifle's inherent accuracy comes from the direct gas impingement.
There is mo moving parts as opposed to a reciprocating piston.

Both have their place, and I feel that for a CQB out to 300m gun the piston fits the bill nicely.

I wouldn't expect to see any piston systems on the Highpower line expecting to be competitive at 600yds however.

 

[JoeSmith]

Re: differerence between gas and piston AR uppers

HTR; SOCOM and big Army has conducted well known studies that did in fact find many problems with the legacy M4 system. (The big Army study was found to have seriously compromised the "facts", but its clear the numbers were played with and someone(s) were caught lying). This led to the Hk416 which is very well liked by those who use it.
Compared to the other systems tested, M4 has a noticable trend to more parts breakage, fouling, and less reliability due to various jamming issues and extraction problems. Not to mention massive problems with cleaning...

 

[Turk]

Re: differerence between gas and piston AR uppers

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Shooter5</div><div class="ubbcode-body">HTR; SOCOM and big Army has conducted well known studies that did in fact find many problems with the legacy M4 system. (The big Army study was found to have seriously compromised the "facts", but its clear the numbers were played with and someone(s) were caught lying). This led to the Hk416 which is very well liked by those who use it.
Compared to the other systems tested, M4 has a noticable trend to more parts breakage, fouling, and less reliability due to various jamming issues and extraction problems. Not to mention massive problems with cleaning... </div></div>
Old news, and I am pretty certain they are "over" the 416 trend by now! The 416 has it's parts breakage issues all of it's own!

 

[JoeSmith]

Re: differerence between gas and piston AR uppers

Ah, so true. Can anyone get the military perfection in a rifle? Now, what's the latest Holy Grail? SCAR?
What I don't quite grasp is why mature technologies like say, the SIG 550 series, aren't adopted more.

 

[RyanScott]

Re: differerence between gas and piston AR uppers

SCAR is a turd. Haven't spoken with a user yet that liked it. Sure is popular on the internet though.

 

[MtGoat]

Re: differerence between gas and piston AR uppers

When I was looking into the available systems I came across one of these...http://primaryweapons.com/store/pc/viewCategories.asp?idCategory=7

I asked around and found a shop in Vegas that was running them full auto....10k rounds through a SBR and it broke. They found the gun shop did the install and drilled the gas port crooked and it eventually broke out the gas block (over 10k rounds later). They replaced the barrel (and hopefully drilled the gas port correctly) and have well over 10k through the second system with no hiccups. Seemed like a fairly rel;iable system so looked into accuracy. Ended up getting an upper from MSTN and it shoots well under 1" 10 shot groups at 100 with factory reloads. It has an 18" barrel and a mid-length system. Not as sexy as others but seems to work....so far. looking to run it as a 3-gun rig....just need to decide on a scope.

Pat

 

[ranger216]

Re: differerence between gas and piston AR uppers

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jephs422</div><div class="ubbcode-body">I'm building another upper but up until recently had never seen the piston style uppers. Can I build this style with a regular bare upper and lower, or are the parts specific to the piston type? And is there anywhere I can get schematics or detailed info on them? </div></div>

Reliability Reliability Reliability, ability to cycle tons of foreign ammo all day with no issues, and 1000's of rounds between cleaning, oh did I mention reliability.

 

[Kells81]

Re: differerence between gas and piston AR uppers

here is a difference, I have a few AR's in the safe, one with about 7k rounds on it, Colt MT6700, great rifle But none of my DI guns have done this to a Extension

Thern again I have never seen a DI AR that clean after even 20 rounds in the upper area.

The downside is like the Ruger that is a pic of, The parts for it have to come from ruger, maybe they will sell replacement parts but as it sits, if it breaks I have to send it back to them. At least for anything related to the upper.

 

[ranger216]

Re: differerence between gas and piston AR uppers

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Poke</div><div class="ubbcode-body">here is a difference, I have a few AR's in the safe, one with about 7k rounds on it, Colt MT6700, great rifle But none of my DI guns have done this to a Extension

Thern again I have never seen a DI AR that clean after even 20 rounds in the upper area.

The downside is like the Ruger that is a pic of, The parts for it have to come from ruger, maybe they will sell replacement parts but as it sits, if it breaks I have to send it back to them. At least for anything related to the upper. </div></div>

Thats 100% carrier tilt, im sure ruger is on thier gen1, maybe fixed down the road.

 

[takeaim1st]

Re: differerence between gas and piston AR uppers

jephs422, If you can afford one of the new Itty-Bitty, ( U.S.-M4-CV ), CATILYTIC CONVERTERS, to install on the old gas system type,they are just about as reliable as the new piston system. The converter does a good job ,stops all that dumping of carbon and other action fouling debris from causing jamming,just when you don't need them.

 

[jephs422]

Re: differerence between gas and piston AR uppers

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: takeaim1st</div><div class="ubbcode-body">jephs422, If you can afford one of the new Itty-Bitty, ( U.S.-M4-CV ), CATILYTIC CONVERTERS, to install on the old gas system type,they are just about as reliable as the new piston system. The converter does a good job ,stops all that dumping of carbon and other action fouling debris from causing jamming,just when you don't need them. </div></div>

do you have a link to what you are referring to? I'd like to check it out.

 

[Kells81]

Re: differerence between gas and piston AR uppers

I think he is fuckin with you

 

[jephs422]

Re: differerence between gas and piston AR uppers

LMFAO I'm an idiot........

 

[paulo_santos]

Re: differerence between gas and piston AR uppers

I have close to 5K rounds through my LMT Piston upper and I've had no real issues with it. It is just as accurate as my DI ARs and I've gone over 1K rounds without cleaning it and it could have gone longer.

In theory you guys are correct in that most people don't need Piston ARs. In reality, most people. That own Piston ARs would not go back to DI if given a choice. Owning a Piston AR is not the same as going to the range and shooting someone's Piston AR is not the same as owning one. Can't really explain it. Most piston uppers are actually very similar and they are past the growing pains as most companies are switching to the 1-piece carriers.

To the OP: If you decide to get one, do some research. It is better to get a complete upper, but if you decide to build our own, the Adam's Arms conversion is one of the most complete kits out there. Handguards are something to consider as there are only a few out there that will work with piston systems.

 

[jephs422]

Re: differerence between gas and piston AR uppers

I am definitely building my own, so I'll check out Adam's Arms. I'm still leaning towards DI, but it doesn't hurt to look. I am in the market for a 16" barrel. I should be able to buy any AR barrel to start right?

 

[paulo_santos]

Re: differerence between gas and piston AR uppers

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jephs422</div><div class="ubbcode-body">I am definitely building my own, so I'll check out Adam's Arms. I'm still leaning towards DI, but it doesn't hurt to look. I am in the market for a 16" barrel. I should be able to buy any AR barrel to start right? </div></div>

I would start with this Daniel Defense 16 Recon Barrel - Mid Length .