Impingement vs Piston

[Big Ray Ray]

Hey guys sorry to be a bother. I'm sure this has been discussed at length here before. However my poor search skills have not found what may be the definitive Piston vs Direct Impingement discussion here. If anyone could provide a link to a good thread it would be greatly appreciated. I'm trying to make a decision on my first AR and unfortunately I have found myself woefully ignorant on the subject. I need to do some serious reading and hear some back and forth on the pros and cons. If possible thanks in advance for the link guys.

Hot babes for your troubles.

 

[Redmanss]

Re: Impingement vs Piston

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Big Ray Ray</div><div class="ubbcode-body">Hey guys sorry to be a bother. I'm sure this has been discussed at length here before. However my poor search skills have not found what may be the <span style="font-weight: bold">definitive</span> Piston vs Direct Impingement discussion here. If anyone could provide a link to a good thread it would be greatly appreciated. I'm trying to make a decision on my first AR and unfortunately I have found myself woefully ignorant on the subject. I need to do some serious reading and hear some back and forth on the pros and cons. If possible thanks in advance for the link guys.

</div></div>"Definitive" is the problem. It doesn't exist because both sides are incapable of being swayed by the other and it ends up being another Ford-Chevy or Glock-1911 argument.

I shoot DI because I've never found cause to pay for and shoot anything else, and I don't fix non-existent problems. There's plenty of reading out there on DI vs. piston stating both sides thoroughly while slamming the other. I sleep just fine at night though.

Use the Google-SH search engine for better results:
http://www.google.com/cse/home?cx=010955838166721108978%3Aqcbx5qqy10o&hl=en

Here's the search already done because the amount of threads on the subject are too many to post:
LMGTFY DI vs Piston

At least he brought hot chicks.....

 

[Tactical_Tom]

Re: Impingement vs Piston

You’re not going to get a definitive answer, people have different opinions. I think that the AR platform is meant to be DI and that the carrier design simple doesn’t have enough guidance by the upper to be easily converted to a piston without creating wear problems. Look at the AR-180 its carrier is what I think a piston type AR carrier should look like.

The disadvantages:
Increased recoil
Carrier is hit of center and don’t have enough support to prevent it from rotating and causing wear to the upper and buffer tube.
Had to make free floating
Deceased accuracy
More parts
Proprietary parts
Cost more

The Advantages:
Runs much cleaner doesn’t vent into the receiver
Less likely to explode if fired with water in the barrel
Works better with a suppressor

Some of the problems have kind of been fixed but…

 

[notquiteright]

Re: Impingement vs Piston

The piston system also runs a bit cooler as the hot gases are not dumped into the receiver.

I'd rather have my charging handle up front than at the back of the receiver on my 308 AR. Cant have a simple cheek pad with a traditional charging handle.

 

[Awesymoto]

Re: Impingement vs Piston

When pistons came out for the AR platform rifles I was the first to wan't to like them. Promises of "reliability beyond comprehension" etc etc. That was until I realized DI rifles aren't nearly as bad as they are slammed for on the net. I have owned, fired, or trained with AK style arms, M4's and Clones, M16's, and AR-10 Platform (to say larger caliber) weapon systems as well as many machine guns of different operating systems.

With that said I have come to the general conclusion you can have any type of operating system but without proper weapons maintenance the desired end result of proper operation will be hard to attain.

Often the word "Piston" or phrase "Piston Driven" is linked to "Reliability" in ones head based off of other designs (AK 47/74 M1A, BAR, M14 etc etc. ) track record of being notoriously reliable. This is true but more so because of the ENTIRE firearm design. The M14 and BAR both fire large powerful cartridges that are capable of driving a high mass piston at a relatively fast speed, allowing the action to be run under a significant amount of force negating the friction caused by dirt and debris to a point... They were also designed with tolerances allowing minor "play" so to allow dirt and debris to move freely around in open spaces preventing the action from binding up. The AK 47 is inaccurate by design due to its parts being loose. This prevents consistency during chambering and firing, allowing micro-variations from shot to shot. With shooting consistency is everything. However the trade off is increased reliability. This is of course a barney breakdown and does not consider the lack of match barrels, and match ammunition.

Lets look at the M249, Piston Driven, but needs to be run wet and clean to function properly. Look at the 240B, Piston Driven but works like a champ in dirt dust etc.. Same operating principal but both have different thresholds of reliability under the same circumstances. The M4 and M16 both function fine and will fire hundreds of rounds wet before major carbon build up will cause them to fail. Regardless of DI or Piston Driven, dirt and debris will both F up your action. The added friction caused between the receiver and BCG will become greater than the force applied from either a piston or gas charge send down the gas tube, or the buffer springs ability to successfully chamber a round into battery. NOW with that said pistons may allow a BCG to be run dry which will attract less dust, allowing you to operate in severe conditions longer before that threshold is met.

Personally DI has worked for me, continues to and in my mind I'd rather clean my BCG and throw some lube on it than clean a BCG and Piston and worry about dirt clogging up my piston. Then again I clean the crap out of my gear.

IMHO If your carrying more than 300 rounds of 5.56 and firing it all in one setting without the ability to piss some lube on your rifle, then you must be either in a really shit situation or were utterly unprepared for what you knew was coming. Train hard to avoid the first, and think hard to avoid the latter.

Technology is no excuse for training. Train to learn to clear type 1,2,3 (and the motor drop) 4 malfunctions in an AR platform. It is stupid not to. The high level of accuracy you receive from the design has some disadvantages, Learn your weapon, its strengths and weaknesses. Nothings perfect.

 

[DMack]

Re: Impingement vs Piston

If the perfect rifle existed, we would all own it. I've run DI guns for over 25 years. They work fine. I now own three piston AR platforms, two AR-15 style, one AR-10 style. They work.

It all boils down to this... find a manufacturer that builds a great product, stands behind their product, gives you great customer service and then pick.

In the end, it's all a matter of taste anymore. The AR platform is saturated with companies that build them, and the vast amount of choice the consumer has today, makes our job a lot harder, and can get overwhelming. As long as you understand the shortcomings of each, then you can be an informed consumer. Not all DI guns are created equal, and this goes for Piston guns as well. This thread would be eleventy-six pages long if all of the nuances of each were discussed.

Some are dressed more nicely than others, but in the heart... you have three things to consider.

1. Operating System
2. Barrel
3. Trigger


Operating System - there are basically three... Direct Impingement, Short Stroke, Long Stroke. The DI system was the original design, and it works fine. The Short Stroke system comes in various flavors... some are conversions, some are designed that way from the factory. Then, you have the long stroke system. I believe that PWS is the only one at this time that are using this design in the AR platform. No matter which system you chose, shoot it, maintain it, and it will last you a lifetime.

Barrel - Not all barrels are created equal. Since you asked DI vs Piston, I wont get into it... but, IMHO, the Barrel is the bigger consideration. How is it made? What rate of twist? What is the intended use? If you buy a lightweight pencil profile 1:9 twist 14.5" barrel, and intend to shoot Service Rifle Class with it, you will fail miserably. On the other hand, if you Choose a 24" HEAVY barrel to serve as your patrol carbine... then, that is a bad choice. Barrel selection is the most important in my book. It will determine how the rifle is to be used.

Trigger - the second most important item. Again, has nothing to do with DI vs Piston. I just wanted to say that most people get entirely wrapped up around the operating system of the rifle, and not the important issues at hand.

In the end, find a rifle that you like. Make sure the barrel is for your intended purpose, and then put a great trigger in it... and the thing will shoot.

DI vs Piston... this is not even debatable in my opinion. It's more a "To each their own" .

This is just the .02 of a hard use kind of guy. One mind... any weapon... one ass to risk.

Cheers,

DMack

 

[Awesymoto]

Re: Impingement vs Piston

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DMack</div><div class="ubbcode-body">One mind... any weapon...<span style="font-weight: bold"> one ass to risk.
</span>
Cheers,

DMack </div></div>
HAHAHAHA changed the motto huh.

 

[Hootiewho]

Re: Impingement vs Piston

If you want to run a 10" or less barreled AR suppressed, the Piston MAY be a decent choice. In longer barrel lengths go DI. I'm not going to get into all pros/cons as those have been hashed over many times in the past.

I will say this, if you want a piston type rifle, buy one that was designed from the ground up as a piston rifle (AK, SIG 55x, SCAR, AUG). if you want an AR, get a DI.

Who said AKs aren't accurate? I beg to differ.

 

[Awesymoto]

Re: Impingement vs Piston

Hootie who... Just talking about stock AK's. vise stock AR's. in general.

 

[chainring]

Re: Impingement vs Piston

Both good, as long as you buy quality versions of either platform. For pistons, that would be LWRCI, POF, or PWS.

 

[Strangedays]

Re: Impingement vs Piston

I shoot both and like both. Most reasons have been already mentioned. I shoot piston for fun and DI for competition because I can tune the gun better than a piston rifle.

 

[Big Ray Ray]

Re: Impingement vs Piston

Thanks for the search link Redman. That's a big help. I'm leaning towards direct impingement simply for parts interchangeability. But would like to research first. Really appreciate the help guys.

 

[crebrosseau]

Re: Impingement vs Piston

I agree with to each their own. I used an M-4 in Iraq and Afghanistan and own a gas piston Bushmaster. I wished I had my gas piston Bushy there every day. I used my piston gun at work and fired hundreds of rounds in one range session, every one else had problems with there DI guns. I had zero. Yes, a cheap piston gun won't be as reliable as a decent DI gun. In that case we had had similar quality weapons (even same brand) just mine was piston. Although I personally think a DI gun has pontential for greater accuracy just how it's designed and how a piston system interacts with the barrel i.e. LaRue OBR vs. POF .308 I guess that's just my $.02

 

[Sapper524]

Re: Impingement vs Piston

I prefer the DI system. The AR platform was designed as a IN LINE system with everything in line with the bore of the rifle. The piston system puts moving mass above the barrel. Is this a huge difference ... to some yes. It adds another moving part to the system which I don't care for. As for the it runs cleaner debate ... I have never had a quality DI rifle fail due to carbon build up.

In the bigger picture ... for the recreational shooter ... its a wash really.

 

[Arbiter]

Re: Impingement vs Piston

It's worth pointing out that some of the perception that "Piston is better!" can be traced to the fact that piston systems, upon their entry to the commercial market, were only available from two or three high-end manufacturers. People tend to naturally associate the reliability with the quality of the brand. Had DPMS or Bushmaster been the first to push piston systems for sale, we might not be having this same discussion.

 

[ANGLICOMarine]

Re: Impingement vs Piston

I just got back from Gunsite and took their carbine course...shot a bone stock Smith and Wesson M&P....not one malfuction, just kept the lube on it...just like I do in country. Shot fine...

 

[scotharr]

Re: Impingement vs Piston

The M16/AR15 was designed as a rifle length DI system and in that incarnation, I think it works flawlessly. One could argue that 14.5" or shorter carbines are not the ideal application of a DI system. But in that case, I'd suggest moving to something designed as a piston system from the ground up like a SCAR or SIG. Of course, a SCAR or SIG does not handle near as nicely as an AR.

I'd also suggest that what one person views as weaknesses are what another will view as strengths: two sides of the same coin. People complain that the DI system is dirty. But the DI system is what gives an AR all of its strengths. It is the most accurate semi-auto in the world, is light, well-balanced, and points very well, with a gentle, inline recoil pulse that allows you to stay on the target...and a rifle or mid-length gas system are completely reliable. For all those strengths, I'm ok with having to clean the BCG.

As a side note, I did put an Adams Arms system on my 20" AR and it went from flawless DI to malfunction prone piston. I probably could have modified the gas port to make the AA function, but decided to return it. Why fix what ain't broke?

 

[chainring]

Re: Impingement vs Piston

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Scooter-PIE</div><div class="ubbcode-body">
....As a side note, I did put an Adams Arms system on my 20" AR and it went from flawless DI to malfunction prone piston. I probably could have modified the gas port to make the AA function, but decided to return it. Why fix what ain't broke? </div></div>

Refer to my earlier post about buying quality versions of either system...

People are going to have problems with the conversions. There are two many variables. If you had gotten an LWRC, I bet you would have had a different experience and a different response to this thread.

 

[KillShot]

Re: Impingement vs Piston

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: chainring</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Scooter-PIE</div><div class="ubbcode-body">
....As a side note, I did put an Adams Arms system on my 20" AR and it went from flawless DI to malfunction prone piston. I probably could have modified the gas port to make the AA function, but decided to return it. Why fix what ain't broke? </div></div>

Refer to my earlier post about buying quality versions of either system...

People are going to have problems with the conversions. There are two many variables. If you had gotten an LWRC, I bet you would have had a different experience and a different response to this thread.

</div></div>


I am in agreement with chainring. Get a PISTON RIFLE instead of a piston CONVERSION and my guess is that you'll feel different about the whole gas-piston setup and debate.

 

[scotharr]

Re: Impingement vs Piston

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: chainring</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Scooter-PIE</div><div class="ubbcode-body">
....As a side note, I did put an Adams Arms system on my 20" AR and it went from flawless DI to malfunction prone piston. I probably could have modified the gas port to make the AA function, but decided to return it. Why fix what ain't broke? </div></div>

Refer to my earlier post about buying quality versions of either system...

People are going to have problems with the conversions. There are two many variables. If you had gotten an LWRC, I bet you would have had a different experience and a different response to this thread.

</div></div>

Well, I have indeed owned an LWRC upper. No complaints about the reliability, but it shot about 6MOA....yes 6" inch 5-shot groups at 100 yards. When I called LWRC to ask about this they shrugged and said it was "within specifications." Now, I don't blame this on the piston system. It's more a testament to the crappy barrel they decided to put on it....and charge $2000 for. An LWRC or PWS system is still based on a platform originally designed as a DI system: sub-optimal in my book. Any "proper" piston system has a BCG that slides on rails to prevent carrier tilt. So, after trying several versions of piston/AR systems my suggestion is stick with DI or get a rifle designed from the ground up as a piston.

 

[jakhamr81]

Re: Impingement vs Piston

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Scooter-PIE</div><div class="ubbcode-body"> ...Any "proper" piston system has a BCG that slides on rails to prevent carrier tilt. So, after trying several versions of piston/AR systems my suggestion is stick with DI or get a rifle designed from the ground up as a piston.</div></div>

Exactly! Plenty of great piston systems already out there.

 

[slowkota]

Re: Impingement vs Piston

My $.02 cents arent worth much...

But I say adjustable piston for suppressed, and DI for everything else

 

[chainring]

Re: Impingement vs Piston

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Scooter-PIE</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: chainring</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Scooter-PIE</div><div class="ubbcode-body">
....As a side note, I did put an Adams Arms system on my 20" AR and it went from flawless DI to malfunction prone piston. I probably could have modified the gas port to make the AA function, but decided to return it. Why fix what ain't broke? </div></div>

Refer to my earlier post about buying quality versions of either system...

People are going to have problems with the conversions. There are two many variables. If you had gotten an LWRC, I bet you would have had a different experience and a different response to this thread.

</div></div>

Well, I have indeed owned an LWRC upper. No complaints about the reliability, but it shot about 6MOA....yes 6" inch 5-shot groups at 100 yards. When I called LWRC to ask about this they shrugged and said it was "within specifications." Now, I don't blame this on the piston system. It's more a testament to the crappy barrel they decided to put on it....and charge $2000 for. An LWRC or PWS system is still based on a platform originally designed as a DI system: sub-optimal in my book. Any "proper" piston system has a BCG that slides on rails to prevent carrier tilt. So, after trying several versions of piston/AR systems my suggestion is stick with DI or get a rifle designed from the ground up as a piston. </div></div>


Ever had a DI fail to group like you expected?

The CHF barrel on the LWRC is excellent, despite your single upper test case results with unkown issues, ammo, and other variables. My 2 LWRC rifles (and a third that belongs to a friend) are all easy sub-moa rifles with decent ammo and a steady hand. I had some impressively crappy groups from a complete Larue upper, but I didn't write off the design or the company based on that one rifle. I put the case that you shouldn't either!

 

[RUTGERS95]

Re: Impingement vs Piston

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Scooter-PIE</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: chainring</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Scooter-PIE</div><div class="ubbcode-body">
....As a side note, I did put an Adams Arms system on my 20" AR and it went from flawless DI to malfunction prone piston. I probably could have modified the gas port to make the AA function, but decided to return it. Why fix what ain't broke? </div></div>

Refer to my earlier post about buying quality versions of either system...

People are going to have problems with the conversions. There are two many variables. If you had gotten an LWRC, I bet you would have had a different experience and a different response to this thread.

</div></div>

Well, I have indeed owned an LWRC upper. No complaints about the reliability, but it shot about 6MOA....yes 6" inch 5-shot groups at 100 yards. When I called LWRC to ask about this they shrugged and said it was "within specifications." Now, I don't blame this on the piston system. It's more a testament to the crappy barrel they decided to put on it....and charge $2000 for. An LWRC or PWS system is still based on a platform originally designed as a DI system: sub-optimal in my book. Any "proper" piston system has a BCG that slides on rails to prevent carrier tilt. So, after trying several versions of piston/AR systems my suggestion is stick with DI or get a rifle designed from the ground up as a piston.</div></div>

I call bs....

no way they said that, no way you shot 6moa (unless it was a bad rifle) and no way they didn't correct the problem or replace it.

I own 3, all sub moa with factory ammo. Many many lwrc owners would probably agree with me

 

[scotharr]

Re: Impingement vs Piston

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: RUTGERS95</div><div class="ubbcode-body">
I call bs....

no way they said that, no way you shot 6moa (unless it was a bad rifle) and no way they didn't correct the problem or replace it.

I own 3, all sub moa with factory ammo. Many many lwrc owners would probably agree with me </div></div>

Well, you're basically calling me a liar, something I doubt you'd do if you knew me. It was an M6A1 upper made before they were acquired. If you check around with people in the know, I think you will find they were indeed using pretty crappy barrels. Hopefully, things have improved since then. None of that speaks to the impingement system and that's got a solid reputation.

 

[chainring]

Re: Impingement vs Piston

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Scooter-PIE</div><div class="ubbcode-body"> <span style="text-decoration: underline"><span style="font-style: italic"><span style="font-weight: bold">It was an M6A1 upper made before they were acquired.</span></span></span> If you check around with people in the know, I think you will find they were indeed using pretty crappy barrels. Hopefully, things have improved since then. None of that speaks to the impingement system and that's got a solid reputation. </div></div>

That explains a LOT! Indeed, things have changed significantly since the old days, before the new ownership. The CHF barrels they are using now are excellent, as is the CS. Some folks still hold the old product and actions of the old owner against the company, but those days have been over for years. Truly an exemplary company, with rifles and innovation that raise the bar.

I submit my recent group at 100 yards with a dirty SPR, using a TR24 optic (German #4 reticle) and FGMM 77gr ammo.

 

[GONIF]

Re: Impingement vs Piston

This nails it short and sweet .<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: slowkota</div><div class="ubbcode-body">My $.02 cents arent worth much...

But I say adjustable piston for suppressed, and DI for everything else

</div></div>

 

[Rem700p]

Re: Impingement vs Piston

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tactical_Tom</div><div class="ubbcode-body">You’re not going to get a definitive answer, people have different opinions. I think that the AR platform is meant to be DI and that the carrier design simple doesn’t have enough guidance by the upper to be easily converted to a piston without creating wear problems. Look at the AR-180 its carrier is what I think a piston type AR carrier should look like.

The disadvantages:
Increased recoil
Carrier is hit of center and don’t have enough support to prevent it from rotating and causing wear to the upper and buffer tube.
Had to make free floating
Deceased accuracy
More parts
Proprietary parts
Cost more

The Advantages:
Runs much cleaner doesn’t vent into the receiver
Less likely to explode if fired with water in the barrel
Works better with a suppressor

Some of the problems have kind of been fixed but…
</div></div>


The disadvantages:
Increased recoil <span style="color: #FF0000">Not increased, just different. Kind of like a quick jolt as opposed to a smooth recoil</span>
Carrier is hit of center and don’t have enough support to prevent it from rotating and causing wear to the upper and buffer tube. <span style="color: #FF0000">There is some, but a few companies have minimized this to an extent</span>
Had to make free floating <span style="color: #FF0000">Nothing wrong with free floating a barrel</span>
Deceased accuracy <span style="color: #FF0000">My LWRC I sold would shoot under MOA all day.</span>
More parts <span style="color: #FF0000">Completely true</span>
Proprietary parts <span style="color: #FF0000">Again, very true.</span>
Cost more <span style="color: #FF0000">Depends on the company. I've seen some expensive DI rifles </span>

with all that being said, I would get DI before going piston. Build your first AR and shoot the shit out of it.

I moved back from piston to DI only because I had so many parts for DI and I wasn't about to load back up on spare part from LWRC. Also, the upper I wanted was half the price of a similar LWRC upper.

My LWRC was an excellent rifle, shot extremely well, had no problems with it. Just wish they weren't so damn expensive.

 

[jasonusvi]

Re: Impingement vs Piston

While not definitive the take I have is:

SBRs - piston gets reliability edge

All Other / non SBR - DI gets accuracy edge and unclear you give up anything

 

[shoepop]

Re: Impingement vs Piston

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jasonusvi</div><div class="ubbcode-body">While not definitive the take I have is:

SBRs - piston gets reliability edge

All Other / non SBR - DI gets accuracy edge and unclear you give up anything </div></div>

I think your take is right on the $.

 

[jakhamr81]

Re: Impingement vs Piston

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jasonusvi</div><div class="ubbcode-body">While not definitive the take I have is:

SBRs - piston gets reliability edge

</div></div>

Why?

 

[shoepop]

Re: Impingement vs Piston

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jakhamr81</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jasonusvi</div><div class="ubbcode-body">While not definitive the take I have is:

SBRs - piston gets reliability edge

</div></div>

Why? </div></div>

I would not go so far as to say they have a reliability edge on a SBR if you fiddle enough with a DI system on one that is not reliable you can get them close to 100%. I can say useing a piston kit will save you a lot of grief if they don't run right out the box. But the biggest advantage on an SBR is cleaning up the crap that ends up in mag well and everywhere else, x2 that if running a suppressor.

 

[jakhamr81]

Re: Impingement vs Piston

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Mark S</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jakhamr81</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jasonusvi</div><div class="ubbcode-body">While not definitive the take I have is:

SBRs - piston gets reliability edge

</div></div>

Why? </div></div>

I would not go so far as to say they have a reliability edge on a SBR if you fiddle enough with a DI system on one that is not reliable you can get them close to 100%. I can say useing a piston kit will save you a lot of grief if they don't run right out the box. But the biggest advantage on an SBR is cleaning up the crap that ends up in mag well and everywhere else, x2 that if running a suppressor.</div></div>

On your first point, you can just as easily end up with a piston system that is not reliable and also cause you much grief(ask me how I know).

On your second point. I have never found a carbon build up in a mag well of a DI system unless I was running suppressed. The reason for that is not the gas coming out of the gas tube, but because the case is being extracted while the suppressor is still under pressure. Now you have all the pressure in that suppressor exiting both out the front and the back; this is true for both a piston gun or gas-impingement.

Your real enemy with adding a suppressor is increased bolt speed/premature bolt unlock and an increase in the cycle rate (which is really only a factor when shooting full auto). A piston rod does not solve either of these problems, but an adjustable gas block could help to mitigate these problems. Even LWRC developed a gas regulator, because they too understood that the piston op rod did not change the way a suppressed weapon fired/ cycled.

 

[timlemons64]

Re: Impingement vs Piston

+1 on Redmanss, Remi700P & Jakhamr81. I have both. I have a POF (piston) that has been an aboslute problem child. I also have two M&P AR15s (gas impingment) and they work flawlessly. I just don't believe the hype about problems pistons supposedly solve. And when suppressed the piston gets just as dirty. Stick with the stoner concept. Mine go bang every time. I wouldn't trust my life on my POF. But my sweet 'lil ARs are accurate and dependable.

 

[jakhamr81]

Re: Impingement vs Piston

I too once drank the kool aid of a piston driven AR being a superior system. I soon found out that the system I had created more problems than it allegedly solved. I may have just had an extreme case of carrier tilt that tore the shit out of my receiver extension, but I honestly did not see any benefit to having piston system over a DI system.

Things a piston gun can do:
1. Keep the BCG cooler
2. Keep carbon from entering the receiver via gas tube, resulting in a slightly cleaner receiver if you do not use a suppressor.

No matter what you believe those are not problems plaguing a DI gas system:
1. The BCG of an Ar15/ M16 or any variant is designed to handle extreme temperatures.
2. An Ar15/ M16 or any variant can be shot dirty and it will function. The problems that plagued early versions of the M16 in Vietnam were mostly due to ball powder being used and causing more fouling than the stick powder that had been used during testing. All you need to do is keep your BCG lightly lubed (which you also have to do in a piston gun) to keep it running. You will have to clean out your bore before you have to clean your receiver/ BCG in either gun.

Yes the HK 416s did perform slightly better over a DI M4 in the Army's endurance testing, (the 416 scored a 99% and the Colt M4 scored a 98% during a 60,000 round endurance test).

I would probably attribute the 416's extra 1% to not burning off the lube as fast as the DI M4 does.

Also keep in mind that this was a slightly better than average gun maker against arguably one of the world's finest gun makers, not some piston conversion kit out of Brownells. I would argue that if HK was to build a DI system it would probably perform better than half of the DI guns currently on the market today.

 

[Brian S.]

Re: Impingement vs Piston

As someone said before when I see companies like larue and the such making their precision rifles with a piston system then I'll look into it. Until then I'll stick with my DI for precision shooting.

 

[chainring]

Re: Impingement vs Piston

Quality, folks...gotta buy quality versions of either system. Carrier tilt is a tired and out-dated issue, relegated only to the ignorant or cheap. Anybody can get a lemon once in a while, but the quality versions of both systems are proven.