AR-15: DI vs Gas Piston, discuss

[orionz06]

Since it seems that all of the threads eventually turn into needless discussion relative to the OP, lets start the talk here.


To those running a gas piston system, what are your experiences with direct impingement and how has your switch to gas piston changed your experiences with the AR-15? Be specific as to which piston system you are using, as not all are created equal. If comparing to a direct impingement gun, please list what DI gun you were running as well. It will keep things in perspective.

[Legion_Prime]

Only because I know what this thread will turn into.

[JB19Kilo]

While I do not personally own a piston AR, I have extensive experience behind a Ruger SR556, which is piston driven from factory. I myself currently only own ARs from Bushmaster, however I have owned Colts, Armalite, and DPMS in the past. All of mine were/are DI. While I do like the piston systems, I would say I prefer DI. The piston system does run a bit cleaner, but not as much as some companies brag. On my DI systems, I notice considerably more carbon buildup in the upper receiver where the gas tube enters, and the area where the gas tube meets the bolt carrier. The trade off is that the piston system unbalances most weapons and makes it front heavy, and it is noticeable. It is for this reason that I prefer the DI systems, as I find them typically more balanced. This of course is not true for all piston driven AR type weapons, some systems feel better than others.

IMHO - At the end of the day there's no "better" option. It's really a matter of preference to the shooter. There's always some sort of trade off and no rifle as all the features to make it perfect, so you'd have to ask yourself if you want more weight balance or less frequency in cleaning.

[FJR86]

IMHO - At the end of the day there's no "better" option. It's really a matter of preference to the shooter. There's always some sort of trade off and no rifle as all the features to make it perfect, so you'd have to ask yourself if you want more weight balance or less frequency in cleaning.

That is well said.

I chose to run a piston system since it will run cleaner. I am a bit fanatic about keeping my guns super clean. It was basically the reason why I decided to go with a piston over DI for my build.

[Kramer]

I chose to run a piston system since it will run cleaner. I am a bit fanatic about keeping my guns super clean. It was basically the reason why I decided to go with a piston over DI for my build.

Word!

I have two LWRC uppers on my ARs that run clean even with a supressor.

Also, piston upper run a lot cooler leading to longer bolt head and extractor life.

[orionz06]

Here are the posts from the root of the discussion:

I'm not really sure what "taking over" means.

If you want a recommendation for a good DI AR-15, I would highly recommend the Knight's Armament SR-15 E3. It's a wonderfully balanced rifle that comes stock with alot of different features. Price is about $1750 - $2000 depending on retailer. It is generally regarded as one of the better DI AR15's, if not the best.

Piston AR's have significant advantages particularly when running them suppressed. The gas system is especially useful for this purpose. It is true that there will be less heat and fouling in the receiver which leads to an extended life compared to DI counterparts.

The HK416 is a very good example of this new generation of piston driven AR's. However, the 416 is more than just an AR with a piston on it. It has a few upgrades.

As an owner of both piston and D.I. AR-15's, I agree with most of what you are saying. Colt is over hyped, and piston weapons offer a better alternative to having to clean carbon encrusted crap from your gun after every trip to the range.

For 99.99% of civilian AR-15 owners and shooters, the piston weapons have a lot to offer with no downside, other than the fact most of the mall ninjas hate them because the "trainers" they worship on a day to day basis, hate them. And these people simply cannot be argued with because they are the only ones licensed to form such opinions.

Be that as it may, my 2 piston AR-15's, (LWRC's), have run like tops for over a full year now. It is so nice to come home after a long range session and have to do only a 5 minute clean and oil as opposed to the long involved ritual of scraping carbon from the bolt and receivers of my D.I. weapons. As a result my LWRC guns get shot a lot more. It's much less of a hassle. After over 40 years of gun ownership and shooting, I've come to appreciate things like that. I still shoot my D.I. weapons, but admittingly I see absolutely no advantage to them from an operational standpoint. And after they've seen enough rounds it's easier to clean my gas barbecue. Bill T.

A better alternative would be a gun that was designed from the ground up as a piston gun. You would retain the benefit of a folding stock and ambi controls that are much better than an AR with converted parts. The SCAR or ACR comes to mind. When you convert things to be something other than designed, the only person winning is the guy selling the parts...

The other issue is you dont need to scrape the bolt tail.

And the final concern with a piston system is recoil, DI has a distinct advantage in this respect, not to mention less weight up front.

You have to be kidding. How you can discuss the word "recoil", let alone attempt to make an issue over it when talking about any AR-15 weapon that shoots 50 grain .22 bullets is beyond me. Which "trainer" did you pick that up from? Bill T.

If I am shooting a tiny 50 grain .22 bullet, I want every advantage out of it I can get. That starts by not adding weight to the end of the gun and reducing impact inside, IE, sticking with how it works now.


FYI, no trainer has told me what opinion to have, and for that matter, I have not been around many trainers to begin with. My opinion has been formed from shooting them and actually learning how they work. Never hurts to be in my profession either.

What "weight"? You are trying to prove a ridiculous point that is totally meaningless in the real world. Not to mention it makes no sense what so ever. Bill T.

Gas block, op rod, springs... you know, everything that replaces what can be a tiny gas block and hollow steel tube. Not to mention balance matters as well.


ETA: If you are just shooting dirt from the bench I suppose it doesn't matter how much shit you toss on the end of it...

What the hell would you do if you had to shoot a M-1? How would hits be possible with all of that tonnage? Bill T.

The Piston vs non-Piston all have their proponents and detractors.

The documented advantages of the 416 for reliability and longevity over it's M4 counterpart is well documented.

I agree 100%, but for those of us that go home at night do the negatives (albeit some minor) add up too much? Also remember that not all piston systems are the H&K 416...

Not even remotely. You've got that move down pat. Perhaps you should look into Airsoft. Lot's of realistic looking weapons out there. Some even have Muzzle Brakes that are effective. Bill T.

http://www.rarguns.com/Complete_Rifles.html

Here you go......check out the LMT upper, Spike Tactical lower (or pretty much any other lower you would like on it) for $700.00

I am in the market for one and am selling a Bushmaster to fund it. I have a Stag M2 and my Bushmaster. I was told they are both great rifles but these are better.

I am at least checking it out so I can get the best rifle for the money. I paid more than $700 for my Stag and my Bushmaster.

I agree that not all pistons are created equal, which is why I can only comment on the 416 as I have 2 and shoot them.

As far as negatives go, I can understand if you want to save every ounce of weight, especially if you are carrying alot of gear. The question becomes is that added weight vs more reliability and longevity and ultimately cost worth it?

I agree that if all you are doing is plinking, these answers may have different values. However, if your life depends on it whether you are in a sandbox or not, these answers also will have different value.

Either way, it's ultimately depends on what the buyer wants

To get back on topic and who makes the best AR15, I think it's fair to say that there are quality AR's at most price points. "Best" would have to be defined better.

The problem is their LMT upper is not the closest thing to the real M4 as they claim it to be.

I would suggest: http://www.bravocompanyusa.com/BCM-1...urg-mid-16.htm

with their BCG and your rear sight of choice, on a lower of choice with an H-buffer.

You will pay a little more, but the link you posted doesn't even state what kind of bolt is in there.

can you provide a citation?

I will side with him, I have read a fair amount in the past on the 416, and of the piston systems, it is probably the only "conversion" worth anything. Several certified armorers I know also agree that the 416 is the only piston system out there that exceeds the reliability of a well maintained TRUE mil-spec DI gun.




Since we are going there, my AR's are my "bump in the night" guns. As far as reliability goes, I have made sure I have every option possible to make it the most reliable, this includes meeting or exceeding mil-spec (if we accept that as the reliability standard). Knowing that I can run 2000 rounds of Russian ammo through it without a single malfunction of the gun tells me it is reliable enough. If I should toss it on an NFA lower with a fun switch, I might find a piston gun to be more reliable, but by no stretch is the Noveske I run unreliable.

As far as what the buyer wants, I tend to base suggestions on them buying something they must trust, anything less is on them.

Quality at a price point... I would say this starts at $800. Anything less requires someone to work on it first, which is a viable option. There are a few $600 guns out there than can work well for someone who wants a range gun only. They would only need an hour or less worth of tweaking.



ETA: Also consider the price of the 416 relative to a BCM or Daniel Defense built that is milspec... I believe the 416 is around $3000, if not more?

You can google it up. There are charts showing the 416 having less stoppages than the M4 during the M4/416/SCAR/XM8 testing.

You can also read the articles in armytimes.com, defensereview.com, they are well circulated on the net I believe.

You can also read the article I posted in the mk23 pistol discussion where Larry Vickers describes the development, testing and it's fielding by Tier 1 units.

I agree with you on reliability. As we agree, there are many good manufacturers. Noveske, LMT, LWRC, KAC (my favorite), Daniel Defense, etc. Generally it boils down to features, ergonomics, and other preferences.

http://randywakeman.com/USArmyM4NationalDisgrace.htm

This pretty well sums up just about everything wrong with the D.I. M-4, along with weapons that can't help but be better choices. Bill T.

ok. thanks for the citations.

You're doing it wrong. Obviously you can take the man out of the military but taking the military out of the man is a bit harder

As far as the weight up front on piston weapons, you are correct that they are a bit heavier up front. However once you get used to the balance, I cant imagine it being much of a factor. There are more parts to a piston driven weapon as well, and theoretically more to go wrong. This though has never been an issue as far as I know. The Delta operators who have used the HK and LWRC piston AR's LOVE them, as they can take MUCH more sand, mud, dirt, etc and withstand the elements far more than a D.I. AR.( just as much abuse as an AK from what I hear). In Iraq and Afghanistan reliability has been a MAJOR issue with the standard AR. I believe piston rifles will completely dominate the civilian market within the next several years. as it is clearly a major improvement of Eugene Stoners design. In the past, the weak link in AR's was the neccesity of keeping it VERY clean, and the lack of quality magazines ( but now there are numerous great mags on the market as well ). The AR platform has now been perfected as much as possible, and the next step in technology is the SCAR, ACR, XCR, etc. Dont get me wrong, as the original AR with DI system is an excellent weapon and if properly maintained and cleaned, functions fine, but in tough conditions ( as in the middle east) thats a BIG if.....anyway, the most important thing is to get something you have confidence in and practice, practice, practice!

I would post more, but it seems as if you need to learn a little more about the gun itself before I do.


The next step you listed IS true, but note that they are ground up piston guns, not a conversion.

Give me a break...you're the one who doesnt know his %$# from a hole in the ground. Piston IS more reliable than DI.. uh...let me see...FN FAL, M1A, AK-47, ALL piston weapons. And piston AR's like the LWRC and the HK416 have been put through tests in mud, dirt, sand, extreme cold, heat, and still functioned realiably WITHOUT cleaning. Try THAT with your Direct Impingement "Colt"......you're clueless buddy.

What is your exposure to Delta operators?

I wont even argue the merits of either system - that's been beaten to death already. I just want to know about your Delta friends feeding you the info on the use of the HK, LWRC piston system.

When did I say the piston wasn't more reliable? Better yet, when did I state that the DI was as reliable?

And if you had read, I agreed with you by stating that modern piston guns are the way of the future, just not a converted gun. The SCAR and ACR are shining examples of a modern piston gun that maintains all of the positives of most guns out there...

The point of contention here is that the DI guns are not some piece of fine china you only use when you have guests.

[orionz06]

continued...

I will agree to a point that piston guns that were built from the ground up can be very good. However, even though the HK416 is a "conversion", I don't see how that makes it inferior.

Folks who are used to the M4/AR15 will have no trouble transitioning to the 416, whereas the SCAR is slightly different.

I would be curious as to why you think conversion guns are not as good.

I dont want to say not as good, but they make poor use of the lower they are tossed on. I will pick the ACR as my "ground up" piston gun.

The ACR has a piston specific bolt set up rather than an piston bolt that fits with AR parts. You no longer have the need for the buffer spring and buffer, or receiver extension for that matter. You can fold the stock down, etc. Extra parts are generally bad. Look at the carrier tilt issues that some piston AR's have. I believe all of them are resolved now, but this was caused by extra parts that werent needed.

Note that I also understand that the 416 was designed to fill a niche, and by design is a "converted" AR. On a random note, are you aware of any testing results for HK's DI upper? Or have I only read speculations of them making one?

I understand your point about the stock and some other features and actually I agree with you. I think that the time and cost of "re-training" and to stockpile parts is one of the reasons why it will take a rather long time for non AR platforms to gain alot of traction in the military. Just recently, the Asymetric Warfare Group was forced to return all their 416's despite their strenuous objections due to the insistence of some to continue using the Colt M4...not only were they not given the M4 that they wanted, they were forced to use the M4, not even the M4A1 that they wanted. The link to the story can be seen here.

http://www.defensereview.com/hk416-c...n-us-army-awg/

From what I've been told by folks who have had experience with these issues, the military on the whole seems to be very slow in adapting new technology. I believe the 416 was actually developed with funds from Delta (although they didn't have to spend much as HK took the bulk of the cost).

The XM8 (HK's futuristic rifle) actually performed very well in tests, but in the end, plans to adopt it were dropped. The G36 and to an extent the SIG 55X (not 556, but the real Swiss rifles), all have a good track record, but for domestic use, they never caught on due to retraining, magazine incompatibility with the AR15 mag and probably more importantly, cost of total replacement.

I do not believe there are any plans for a DI rifle by HK. HK's civilian version of the HK416, the MR556 and it's sister the .308 MR762, are due for release. The MR556 is already released in Canada and Europe, but not yet in the US due to import regulations. The new MR556 will be manufactured at the Wilcox facility in Newington, NH. Originally, the MR556 lower would not be compatible with standard AR15s as they were going to move the pin. However, this has been changed and now the HK lower and upper will be compatible with standard AR15 lowers and uppers. Essentially this will allow folks to buy a civilian upper at some point, or swap out the lower. Also, this will allow the mil/LE 416s to be put on SBR'd MR556 lowers. This is what I plan to do with mine.

I've never handled an ACR, but I do have a SCAR. If you have handled one, what are your impressions? I havent shot mine, but after handling it, I was not overly impressed.

The military is extremely slow (understatement) and not always right when they do change. Consider the lubrication concerns and their standards...

I know Larry Vickers had a large hand in the 416, but it should also be noted that he has mentioned (on his show) that he has no concerns heading into harms way with an M4 (he did not mention brand, so I will give this statement more credit).

ACR... Like an improved SCAR but it just feels big to me. It seems great for a first gen, but the size is akward. I think it had more to do with it being plastic than anything. I would like to get some time shooting one, but who knows.

I will try to gather the points everyone is making here and work on a DI vs Piston (for Stoner rifles) later on.

It should be able to catch a lot of the side talk that is good (most of it) and prevent some of this from not answering the questions being posed.

apples and oranges. those guns are not AR style weapons.

the question is are piston *ARs* more reliable than DI *ARs*.

so far, with the exception of the the HK416, many who see a lot of AR style weapons run hard (professional trainers) report seeing more failures with piston ARs than with DI ARs.

not to mention it is a solution in search of a problem. DI ARs are quite reliable.

Old thread but my .02 is if you are talking straight direct impingement, then my top tier rifle makers are LMT and Noveske...

That being said, I'm all about the new piston style AR's that are coming out...I hate having to clean my bcg......

No, actually it was caused by design. Not intentionally of course, however most kits going with a short stroke piston design transfers the rearward force of the piston at the top of the carrier as opposed to a DI rifle which pushes back on the back of the bolt which then pushes back the carrier. A long stroke piston system avoids the issue of carrier tilt as the piston attached to to the carrier acts as a stabilizer as it travels back with the carrier.



AKA - Law of diminishing returns



I'll see your Weaponshield and raise you SLIP2000 :P

Not intentional, to me, is an issue, but I think we are saying the same thing. Either way, there are acceptable solutions for either system.



I am still working on a thread for this discussion, and that is where it is heading.




I am gonna try the Amsoil I run in my car next, just because I can...

I'm not really sure what "taking over" means.

If you want a recommendation for a good DI AR-15, I would highly recommend the Knight's Armament SR-15 E3. It's a wonderfully balanced rifle that comes stock with alot of different features. Price is about $1750 - $2000 depending on retailer. It is generally regarded as one of the better DI AR15's, if not the best.

Piston AR's have significant advantages particularly when running them suppressed. The gas system is especially useful for this purpose. It is true that there will be less heat and fouling in the receiver which leads to an extended life compared to DI counterparts.

The HK416 is a very good example of this new generation of piston driven AR's. However, the 416 is more than just an AR with a piston on it. It has a few upgrades.

As an owner of both piston and D.I. AR-15's, I agree with most of what you are saying. Colt is over hyped, and piston weapons offer a better alternative to having to clean carbon encrusted crap from your gun after every trip to the range.

For 99.99% of civilian AR-15 owners and shooters, the piston weapons have a lot to offer with no downside, other than the fact most of the mall ninjas hate them because the "trainers" they worship on a day to day basis, hate them. And these people simply cannot be argued with because they are the only ones licensed to form such opinions.

Be that as it may, my 2 piston AR-15's, (LWRC's), have run like tops for over a full year now. It is so nice to come home after a long range session and have to do only a 5 minute clean and oil as opposed to the long involved ritual of scraping carbon from the bolt and receivers of my D.I. weapons. As a result my LWRC guns get shot a lot more. It's much less of a hassle. After over 40 years of gun ownership and shooting, I've come to appreciate things like that. I still shoot my D.I. weapons, but admittingly I see absolutely no advantage to them from an operational standpoint. And after they've seen enough rounds it's easier to clean my gas barbecue. Bill T.

A better alternative would be a gun that was designed from the ground up as a piston gun. You would retain the benefit of a folding stock and ambi controls that are much better than an AR with converted parts. The SCAR or ACR comes to mind. When you convert things to be something other than designed, the only person winning is the guy selling the parts...

The other issue is you dont need to scrape the bolt tail.

And the final concern with a piston system is recoil, DI has a distinct advantage in this respect, not to mention less weight up front.

You have to be kidding. How you can discuss the word "recoil", let alone attempt to make an issue over it when talking about any AR-15 weapon that shoots 50 grain .22 bullets is beyond me. Which "trainer" did you pick that up from? Bill T.

If I am shooting a tiny 50 grain .22 bullet, I want every advantage out of it I can get. That starts by not adding weight to the end of the gun and reducing impact inside, IE, sticking with how it works now.


FYI, no trainer has told me what opinion to have, and for that matter, I have not been around many trainers to begin with. My opinion has been formed from shooting them and actually learning how they work. Never hurts to be in my profession either.

What "weight"? You are trying to prove a ridiculous point that is totally meaningless in the real world. Not to mention it makes no sense what so ever. Bill T.

Gas block, op rod, springs... you know, everything that replaces what can be a tiny gas block and hollow steel tube. Not to mention balance matters as well.


ETA: If you are just shooting dirt from the bench I suppose it doesn't matter how much shit you toss on the end of it...

What the hell would you do if you had to shoot a M-1? How would hits be possible with all of that tonnage? Bill T.

[orionz06]

continued...

The Piston vs non-Piston all have their proponents and detractors.

The documented advantages of the 416 for reliability and longevity over it's M4 counterpart is well documented.

I agree 100%, but for those of us that go home at night do the negatives (albeit some minor) add up too much? Also remember that not all piston systems are the H&K 416...

Not even remotely. You've got that move down pat. Perhaps you should look into Airsoft. Lot's of realistic looking weapons out there. Some even have Muzzle Brakes that are effective. Bill T.

http://www.rarguns.com/Complete_Rifles.html

Here you go......check out the LMT upper, Spike Tactical lower (or pretty much any other lower you would like on it) for $700.00

I am in the market for one and am selling a Bushmaster to fund it. I have a Stag M2 and my Bushmaster. I was told they are both great rifles but these are better.

I am at least checking it out so I can get the best rifle for the money. I paid more than $700 for my Stag and my Bushmaster.

I agree that not all pistons are created equal, which is why I can only comment on the 416 as I have 2 and shoot them.

As far as negatives go, I can understand if you want to save every ounce of weight, especially if you are carrying alot of gear. The question becomes is that added weight vs more reliability and longevity and ultimately cost worth it?

I agree that if all you are doing is plinking, these answers may have different values. However, if your life depends on it whether you are in a sandbox or not, these answers also will have different value.

Either way, it's ultimately depends on what the buyer wants

To get back on topic and who makes the best AR15, I think it's fair to say that there are quality AR's at most price points. "Best" would have to be defined better.

The problem is their LMT upper is not the closest thing to the real M4 as they claim it to be.

I would suggest: http://www.bravocompanyusa.com/BCM-1...urg-mid-16.htm

with their BCG and your rear sight of choice, on a lower of choice with an H-buffer.

You will pay a little more, but the link you posted doesn't even state what kind of bolt is in there.

can you provide a citation?

I will side with him, I have read a fair amount in the past on the 416, and of the piston systems, it is probably the only "conversion" worth anything. Several certified armorers I know also agree that the 416 is the only piston system out there that exceeds the reliability of a well maintained TRUE mil-spec DI gun.




Since we are going there, my AR's are my "bump in the night" guns. As far as reliability goes, I have made sure I have every option possible to make it the most reliable, this includes meeting or exceeding mil-spec (if we accept that as the reliability standard). Knowing that I can run 2000 rounds of Russian ammo through it without a single malfunction of the gun tells me it is reliable enough. If I should toss it on an NFA lower with a fun switch, I might find a piston gun to be more reliable, but by no stretch is the Noveske I run unreliable.

As far as what the buyer wants, I tend to base suggestions on them buying something they must trust, anything less is on them.

Quality at a price point... I would say this starts at $800. Anything less requires someone to work on it first, which is a viable option. There are a few $600 guns out there than can work well for someone who wants a range gun only. They would only need an hour or less worth of tweaking.



ETA: Also consider the price of the 416 relative to a BCM or Daniel Defense built that is milspec... I believe the 416 is around $3000, if not more?

You can google it up. There are charts showing the 416 having less stoppages than the M4 during the M4/416/SCAR/XM8 testing.

You can also read the articles in armytimes.com, defensereview.com, they are well circulated on the net I believe.

You can also read the article I posted in the mk23 pistol discussion where Larry Vickers describes the development, testing and it's fielding by Tier 1 units.

I agree with you on reliability. As we agree, there are many good manufacturers. Noveske, LMT, LWRC, KAC (my favorite), Daniel Defense, etc. Generally it boils down to features, ergonomics, and other preferences.

http://randywakeman.com/USArmyM4NationalDisgrace.htm

This pretty well sums up just about everything wrong with the D.I. M-4, along with weapons that can't help but be better choices. Bill T.

ok. thanks for the citations.

You're doing it wrong. Obviously you can take the man out of the military but taking the military out of the man is a bit harder

As far as the weight up front on piston weapons, you are correct that they are a bit heavier up front. However once you get used to the balance, I cant imagine it being much of a factor. There are more parts to a piston driven weapon as well, and theoretically more to go wrong. This though has never been an issue as far as I know. The Delta operators who have used the HK and LWRC piston AR's LOVE them, as they can take MUCH more sand, mud, dirt, etc and withstand the elements far more than a D.I. AR.( just as much abuse as an AK from what I hear). In Iraq and Afghanistan reliability has been a MAJOR issue with the standard AR. I believe piston rifles will completely dominate the civilian market within the next several years. as it is clearly a major improvement of Eugene Stoners design. In the past, the weak link in AR's was the neccesity of keeping it VERY clean, and the lack of quality magazines ( but now there are numerous great mags on the market as well ). The AR platform has now been perfected as much as possible, and the next step in technology is the SCAR, ACR, XCR, etc. Dont get me wrong, as the original AR with DI system is an excellent weapon and if properly maintained and cleaned, functions fine, but in tough conditions ( as in the middle east) thats a BIG if.....anyway, the most important thing is to get something you have confidence in and practice, practice, practice!

I would post more, but it seems as if you need to learn a little more about the gun itself before I do.


The next step you listed IS true, but note that they are ground up piston guns, not a conversion.

Give me a break...you're the one who doesnt know his %$# from a hole in the ground. Piston IS more reliable than DI.. uh...let me see...FN FAL, M1A, AK-47, ALL piston weapons. And piston AR's like the LWRC and the HK416 have been put through tests in mud, dirt, sand, extreme cold, heat, and still functioned realiably WITHOUT cleaning. Try THAT with your Direct Impingement "Colt"......you're clueless buddy.

What is your exposure to Delta operators?

I wont even argue the merits of either system - that's been beaten to death already. I just want to know about your Delta friends feeding you the info on the use of the HK, LWRC piston system.

When did I say the piston wasn't more reliable? Better yet, when did I state that the DI was as reliable?

And if you had read, I agreed with you by stating that modern piston guns are the way of the future, just not a converted gun. The SCAR and ACR are shining examples of a modern piston gun that maintains all of the positives of most guns out there...

The point of contention here is that the DI guns are not some piece of fine china you only use when you have guests.

I will agree to a point that piston guns that were built from the ground up can be very good. However, even though the HK416 is a "conversion", I don't see how that makes it inferior.

Folks who are used to the M4/AR15 will have no trouble transitioning to the 416, whereas the SCAR is slightly different.

I would be curious as to why you think conversion guns are not as good.

I dont want to say not as good, but they make poor use of the lower they are tossed on. I will pick the ACR as my "ground up" piston gun.

The ACR has a piston specific bolt set up rather than an piston bolt that fits with AR parts. You no longer have the need for the buffer spring and buffer, or receiver extension for that matter. You can fold the stock down, etc. Extra parts are generally bad. Look at the carrier tilt issues that some piston AR's have. I believe all of them are resolved now, but this was caused by extra parts that werent needed.

Note that I also understand that the 416 was designed to fill a niche, and by design is a "converted" AR. On a random note, are you aware of any testing results for HK's DI upper? Or have I only read speculations of them making one?

I understand your point about the stock and some other features and actually I agree with you. I think that the time and cost of "re-training" and to stockpile parts is one of the reasons why it will take a rather long time for non AR platforms to gain alot of traction in the military. Just recently, the Asymetric Warfare Group was forced to return all their 416's despite their strenuous objections due to the insistence of some to continue using the Colt M4...not only were they not given the M4 that they wanted, they were forced to use the M4, not even the M4A1 that they wanted. The link to the story can be seen here.

http://www.defensereview.com/hk416-c...n-us-army-awg/

From what I've been told by folks who have had experience with these issues, the military on the whole seems to be very slow in adapting new technology. I believe the 416 was actually developed with funds from Delta (although they didn't have to spend much as HK took the bulk of the cost).

The XM8 (HK's futuristic rifle) actually performed very well in tests, but in the end, plans to adopt it were dropped. The G36 and to an extent the SIG 55X (not 556, but the real Swiss rifles), all have a good track record, but for domestic use, they never caught on due to retraining, magazine incompatibility with the AR15 mag and probably more importantly, cost of total replacement.

I do not believe there are any plans for a DI rifle by HK. HK's civilian version of the HK416, the MR556 and it's sister the .308 MR762, are due for release. The MR556 is already released in Canada and Europe, but not yet in the US due to import regulations. The new MR556 will be manufactured at the Wilcox facility in Newington, NH. Originally, the MR556 lower would not be compatible with standard AR15s as they were going to move the pin. However, this has been changed and now the HK lower and upper will be compatible with standard AR15 lowers and uppers. Essentially this will allow folks to buy a civilian upper at some point, or swap out the lower. Also, this will allow the mil/LE 416s to be put on SBR'd MR556 lowers. This is what I plan to do with mine.

I've never handled an ACR, but I do have a SCAR. If you have handled one, what are your impressions? I havent shot mine, but after handling it, I was not overly impressed.

The military is extremely slow (understatement) and not always right when they do change. Consider the lubrication concerns and their standards...

I know Larry Vickers had a large hand in the 416, but it should also be noted that he has mentioned (on his show) that he has no concerns heading into harms way with an M4 (he did not mention brand, so I will give this statement more credit).

ACR... Like an improved SCAR but it just feels big to me. It seems great for a first gen, but the size is akward. I think it had more to do with it being plastic than anything. I would like to get some time shooting one, but who knows.

I will try to gather the points everyone is making here and work on a DI vs Piston (for Stoner rifles) later on.

It should be able to catch a lot of the side talk that is good (most of it) and prevent some of this from not answering the questions being posed.

apples and oranges. those guns are not AR style weapons.

the question is are piston *ARs* more reliable than DI *ARs*.

so far, with the exception of the the HK416, many who see a lot of AR style weapons run hard (professional trainers) report seeing more failures with piston ARs than with DI ARs.

not to mention it is a solution in search of a problem. DI ARs are quite reliable.

Old thread but my .02 is if you are talking straight direct impingement, then my top tier rifle makers are LMT and Noveske...

That being said, I'm all about the new piston style AR's that are coming out...I hate having to clean my bcg......

No, actually it was caused by design. Not intentionally of course, however most kits going with a short stroke piston design transfers the rearward force of the piston at the top of the carrier as opposed to a DI rifle which pushes back on the back of the bolt which then pushes back the carrier. A long stroke piston system avoids the issue of carrier tilt as the piston attached to to the carrier acts as a stabilizer as it travels back with the carrier.



AKA - Law of diminishing returns



I'll see your Weaponshield and raise you SLIP2000 :P

Not intentional, to me, is an issue, but I think we are saying the same thing. Either way, there are acceptable solutions for either system.



I am still working on a thread for this discussion, and that is where it is heading.




I am gonna try the Amsoil I run in my car next, just because I can...

[westbound]

BTW, just one last thing...ive owned BOTH DI and Piston AR's and I dont miss having to clean out all the crap from the DI every time you want to shoot it (and my piston AR never had a malfunction.....NEVER ). Well, Im through wasting my valuable time trying to prove whats already been proven by many others. Some people cant handle change in whatever form it takes....

[orionz06]

BTW, just one last thing...ive owned BOTH DI and Piston AR's and I dont miss having to clean out all the crap from the DI every time you want to shoot it (and my piston AR never had a malfunction.....NEVER ).

Thank you for clarifying that you have owned both. What issues did you have with the DI gun? Was it malfunctioning? You state that it needed to be cleaned every time you wanted to shoot it, but what was it doing?

Well, Im through wasting my valuable time trying to prove whats already been proven by many others. Some people cant handle change in whatever form it takes....

What makes you think I cant handle change? What are you trying to prove? I have agreed on the superiority of piston guns in some circumstances, maybe you didnt read that part.

My point was that most highly regarded battle rifles are of one kind or another of piston operation.

Correct, that doesnt mean that gas piston is the only way. There are lots of people out there making stuff work just fine. Also note that Larry Vickers, who I will assume we can accept as an expert, has stated that the FAL was not as reliable as most other guns.

And who are these "instructors" that have experienced less reliability with piston guns. where do they instruct?

I dont know off hand who was implied with that quote. I do know of one person who will not be named that has mentioned many issues with piston guns and a lack of reliability in many classes he has been in.

Here is a pic I took of a piston gun going down:


Locked up pretty good actually. To my knowledge, of ~10,000 rounds fired, this was the only gun to lock up and demand the attention of a group. I had one malfunction of my own, but it was due to mud in the magazine as it was raining pretty good for part of the weekend.

Yes, I can see that happening with a home built or a poorly assembled off brand. Show me an HK416 or LWRC that is less reliable....

I have less knowledge of the LWRC, but I know the 416 is more reliable in most conditions, with the exception of an early test that had the 416 scoring very poorly. They got that corrected in a very short time in terms of firearms development. I also believe my comments have been quite favorable of the 416, which follows suit with my desire to own one...

remember that the top AR manufacturers and other large gun companies ( Ruger, S&W) piston ar's have only
just recently started making these.

My personal opinion is if they wanted to make a piston gun they should have made a piston gun, not a converted AR...

Para has the idea down, but they used a 1/9 twist...

http://www.paraord.com/new/product_rifle.php#specs

The rest are just cashing in on their name. The buyers will have no clue what they are getting.

And BTW, there is also no standard piston mechanism, as all these firms have different designs. I'm not saying that EVERY piston AR is more reliable than DI, only that the best examples of them are hands down more durable and reliable.

And again, I agreed, but dont shortchange a good DI gun. Based on a sampling of ~17 (my best recollection after counting), there was one lock up with a piston gun and none with the other 16 DI guns. But again, only a small sampling.

The other question: Is the LWRC (because the 416 is outrageous) worth more than the BCM?

http://www.lwrci.com/p-21-m6a1-556-uppers.aspx ($1584)

http://www.bravocompanyusa.com/BCM-B...omegax%209.htm ($935+$65)


So is the piston worth $584 more? That is the question we have here. Are the odds that the same user will have better performance out of the piston gun? Lets say you run each to 2000 rounds, is that a fair time frame between teardowns for both guns?

You responses are vague and you cite no specifics. And again, I disagree that I have more to "Learn" than you

If they seem vague, there is a reason. As far as learning, I will wait for a response to a question above first.

Who said I didnt have anything to learn anyway? There is quite a bit out there to read on this subject alone, as well as the application of stuff I know from work and school. It is pretty neat how everything can tie together in some cases.

as you need to put the time in and not just get your knowledge from other bloggers....

Some bloggers and posters are active duty overseas right now. Are their statements and accounts not acceptable? If so, how can we accept what your friend says?

And as far as how I know about Delta, my closest friend was in Delta many years ago, operated covertly in central and South America. He has done and seen things that none of us can ever conceive of. He still keeps in touch with some old friends still in the service to keep abreast of events.

I dont intend to question who/what your friend is or has done.

I also READ a lot and talk to people.

You just implied that was bad... I am confused...