AR Trend or Fad?

[W.E.G.]

Its about marketing, not practicality or utility, or durability.

You are a gun manufacturer.
It costs you the same amount of money to build either format.

There is a market for the piston gun for $500 more per copy.

That's a no-brainer.

P.T. Barnum said...

 

[taliv]

except it doesn't cost the same. there's a ton of development work that went into each of the different piston designs (well, a couple of them anyway... clearly there were no engineers involved in some of the projects), whereas everybody's DI parts are the same and even interchangeable. there are more parts in GP. more machining. more testing. more logistics. more risk.

 

[R.W.Dale]

To each his own. But I do get a chuckle when I see a 30HRT that's built around a piston system. I mean come on how high a round count is expected from a chambering that requires each cartridge to be hand crafted with love and care.

I also wonder how these piston systems stack up in the accuracy dpt. All along the beauty of DI ar15's was there ain't a lot of crap hanging off the barrel.

 

[dispatch55126]

I thought I was answering that, but I'll put it more directly.

Every other major semiauto centerfire rifle is a piston system. Every new design recently has been.

There's no sign that DI is the direction of current gun designers.

I'm not saying it shouldn't be, just that it really isn't. I like it. The AR is about as close to a bolt-action as a semiauto gets, WRT cleaning and maintenance.

What the future holds? That's anyone's guess.

This is what I was referring to. I'm not trying to which is better/why. If that was the case, I'd just start a AR/AK thread. My question revolves around whether you think the gas piston will eventually outsell the DI system. They cost more now but the more that is sold, the lower the price should go. If the price/quality was the same, would people gravitate to a GP system?

 

[cyclopsshooter]

seems to me that some of the most produced firearms in history are the ones that are constantly ragged on about reliability- AR gas impingement, 1911s and so forth-

these firearms are everywhere, does it not make sense to assume that you hear more about them because there ARE more of them?

it just so happens that ARs and 1911s are the number one toy boxes... everyone and their uncle picks these platforms to build or tinker with... doubtful that they ALL know what they are doing...

failed and successful builds both end up at the used gun store making its way into average joe's hands

a few weeks ago at my store i bought a customers M&P-15 for inventory... it was a full size rifle (Smith only makes 16") I knew it was a frankenbuild... but not every gun buyer would know that

if someone says their gun jams your first thought should not be about the gun, but rather the shooter being a novice, inexperienced shooters have frequent problems from improper gun handling skills. further, they do not have the experience to spot poor quality firearms... experts seldom face these problems

 

[Grantman]

I also wonder how these piston systems stack up in the accuracy dpt. All along the beauty of DI ar15's was there ain't a lot of crap hanging off the barrel

David Fortier admitted thinking gp would be comparatively less accurate but found otherwise.
http://www.pof-usa.com/Fortier72006.pdf


dispatch55126 I would wager that if the AR had similarly priced DI and GP systems that it would only be a matter of time before the GP variant dominated it in sales and popularity. DI has tellingly failed to revolutionise or even influence small arms development in the near half century it has been fielded in the m16. It stands isolated in the m16. Inevitably DI will fade back into nonexistence militarily and eventually domestically.

 

[MCMXI]

I also wonder how these piston systems stack up in the accuracy dpt. All along the beauty of DI ar15's was there ain't a lot of crap hanging off the barrel.

Last weekend I shot my new POF SPR at 100 yards using some reloads. I discovered that the scope mount was moving on the rail and subsequently have ordered a mount from GG&G. Anyway, my best 5-shot group prone with a bipod is shown below. I think that the mount was moving slightly during each shot. The last group also shown was going to be well under an inch but the last shot was inexplicably way off ... could have been the mount again. Once I get the load figured out and a secure mount, I have no doubt that the POF will be a sub-moa rifle out to at least 300 yards. I'll prove that too at the next match (or the one after).

I'll be zeroing a new scope (1.5-5x) on my POF (.223) this weekend so I'll post some 5-shots groups at 100 yards once the scope is dialed in.

 

[MCMXI]

Grantman, I had no idea that the gas plug on the POF rifles is an FAL design ... good to know.

 

[Evil Monkey]

DI has tellingly failed to revolutionise or even influence small arms development in the near half century it has been fielded in the m16. It stands isolated in the m16. Inevitably DI will fade back into nonexistence militarily and eventually domestically.

I'm thinking the main reason for this is maybe because some engineers are not very enthusiastic about having to use a gas key, or gas rings, or other parts that can be eliminated through a different design.

An anti-DI design can also stem from having problems actually implemeting Direct Impingment. Have you ever seen a French MAS 49? It uses DI, but instead of using the bolt as leverage to push the carrier back, the gas just impacts the carrier directly to unlock the bolt.

What's the big deal? The big deal is the MAS49 doesn't need a gas key or gas rings and doesn't need to release excess gas from the carriers exhaust ports and out the ejection port like the AR15 does. This is because the MAS49 doesn't have an ak/fal style dust cover or enclosed receiver around the chamber/magwell/gas tube opening. All excess gas goes straight into the air.


I'm guessing that if an AR15 was built to operate exactly like the MAS49, you'd blow out the magazine every time you fired it. Probably even damage the upper receiver.

If an engineer doesn't want a slightly more complex carrier group arangement (like the ar15), or wants an enclosed monolithic receiver, the easiest way to solve the problem is by introducing a piston so that the excess gas can be exhausted in front of the rifle from the gas block.

 

[THE DARK KNIGHT]

it's in response to gun writers who spend more time behind a keyboard than they do pulling a trigger on dirty rifles

+1

Most gun writers and even forum dwellers spend more time discussing the possible ramifications of the zombie apocalypse, or how they'd defend their home from a gang of two dozen murderous thugs than shooting a target at the range. DI is fine, Piston is fine.

 

[Grantman]

Nice 1848, goes to show well made GP ARs are definitely not lagging behind their DI counterparts.

I'm thinking the main reason for this is maybe because some engineers are not very enthusiastic about having to use a gas key, or gas rings, or other parts that can be eliminated through a different design.

An anti-DI design can also stem from having problems actually implemeting Direct Impingment. Have you ever seen a French MAS 49? It uses DI, but instead of using the bolt as leverage to push the carrier back, the gas just impacts the carrier directly to unlock the bolt.

What's the big deal? The big deal is the MAS49 doesn't need a gas key or gas rings and doesn't need to release excess gas from the carriers exhaust ports and out the ejection port like the AR15 does. This is because the MAS49 doesn't have an ak/fal style dust cover or enclosed receiver around the chamber/magwell/gas tube opening. All excess gas goes straight into the air.

Yes the Swedish AG-42B Ljungman and Egyptian Hakim also vent DI gas into the open once the carrier has travelled rearward sufficiently.

I'd imagine designers would be less concerned about weighing up components dealing with internal pressures vs the added components of a gas piston design than they would about achieving premium reliability myself.

 

[C-grunt]

My only complaint with the DI is the cleaning. But then again its not that hard to clean an AR. Keeping an AR serviceable in the field takes less than 5 minutes a day, if that. I just got done with my departments rifle class where we shot a few thousand rounds over 4 days using the brand new Bushmasters Dvid Spade bought us (thank you). It was pretty harsh conditions. 115 degree weather, windy, blowing dust with dust devils swirling about and we were outside the entire 10 hours each day. I oiled it every morning and at lunch and never had a single malfunction.

 

[MCMXI]

Nice 1848, goes to show well made GP ARs are definitely not lagging behind their DI counterparts.

Thanks ... it's going to get better I'm sure. I had no idea as to what to expect so I'm impressed with the out-of-the-box accuracy.

I think we all know that GP systems run a lot cleaner in terms of the BCG but that also applies to the trigger components and magazines. I just got through installing a Geissele SSA trigger and the instructions mention dirt in the trigger and the need for regular cleaning.

From Geissele SSA instructions ...

"When the trigger and lower receiver become very dirty (such as when firing with a suppressor) it is not always necessary to remove the trigger group for cleaning."

This is what Zak alluded to.

 

[gunnie]

..."I think we all know that GP systems run a lot cleaner in terms of the BCG but that also applies to the trigger components and magazines."...

+1

...""When the trigger and lower receiver become very dirty (such as when firing with a suppressor)...This is what Zak alluded to."...

+1

but something not mentioned yet is MUCH higher reciever temps from gasses vented into a pretty much completely enclosed housing in prolonged firing. sure, most people don't go burning copious rounds in short periods of time. perhaps non issue for all but a fully or intense battlefield scenarios, but a real consideration between the two options.

gunnie

 

[mp5a3]

According to Mr. Noveske, there's no advantage using a suppresor with a gas piston..

http://www.defensereview.com/novesk...ecce-carbine-john-noveske-interview-part-one/

Crane: You’re not doin’ a piston gun, right?

Noveske: No.

Crane: Do you have any plans to do a piston gun?

Noveske: We have piston plans, but we don’t have any plans of putting it in production, because it’s…I don’t think it’s necessary. I’ve got piston guns here from other makers, and they’re dirty, and I don’t see…

Crane: Whadya’ mean "dirty"?

Noveske: Open up the bolt and look inside, and it’s dirty inside. The whole thing about them running clean is not necessarily…o.k., let me back up. I only run the guns with suppressors for testing when I did my comparison, and with suppressors, direct-impingement and piston-operated were both very dirty, ’cause the blowback comes to the chamber, not the gas tube. And, I’m not real happy with the piston systems that I’ve shot and examined, so it’s just to me, it’s not…

Crane: Well, the piston…the advantage for a piston with a suppressor on there is supposedly it doesn’t blow all the gunk back in your face.

Noveske: O.k., but what you’re not paying attention to is that all that crap comes back through the chamber, not the gas tube. On a piston gun or gas-impingement, 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.

Crane: Right, but you’re saying the piston gun doesn’t solve that?

Noveske: It does not solve that. They’re both dirty.

Crane: So then how come you hear about guys saying yeah, when they’re shootin’ the direct gas impingement guns suppressed, or whatever, they’re gettin’ a lot of gas and particulate matter in their face, whereas with the piston, that it dissipates that a bit, or whatever.

Noveske: Maybe they had a different experience.

Crane: Hm. So, in other words, you’re saying that basically the piston doesn’t really offer any real advantage for that.

Noveske: What I’m saying, with a suppressor, direct-impingement and gas-piston both run dirty, and even a blowback gun or a delayed-blowback gun, like an H&K [Heckler & Koch], or any other operating system–I don’t really care what operating system you have–on an auto-loader, with a sound suppressor, they’re gonna’ all run dirty.

Crane: Right. Now, is a piston gun gonna’ put any less gas and particulate matter in your face, or are you gonna’ get the same amount?

Noveske: All a piston gun is gonna’ do different from gas impingement with a suppressor is reduce the amount that is coming through the gas tube. The piston gun is gonna’ eliminate that. I am not a scientist, but from my observations in shooting and examining the guns afterwards, it appears that the vast majority of the gas coming through is coming through the chamber. And, one example is go look at any of the HK91 or HK93-type rifles. Those have the fluted chamber and delayed blowback, and the cases are always black just like the case fired out of the gun with a suppressor. That’s because the case is extracting while it is still under pressure, and you have gas blowing back along the case as it’s blowing out, and covering it with carbon. And, that’s what’s happening with any autoloader with a suppressor. The cases all have carbon on them, because gas is escaping around the case out the chamber and into the receiver.

[DefenseReview received the following post-interview via email from John Noveske: "Also, we should mention the poor choice of platform for the piston conversion on a round receiver bore as found on the M16/M4 system. All other piston type systems out there utilize a railed receiver design, like the M14, AK-47, M249, FAL and so on. The round receiver bore design used on the M4 is only acceptable for the standard op system. The carrier and bolt expand on axis with the bore under the normal gas impingement cycle, but on a piston gun, you run into off center impulse issues with carrier tilt and incorrectly designed carrier contact points. Some designs attempt to address the carrier tilt problem with over sized carrier tails and rollers. I do not believe the receiver extension should be used in this manor. I know many people are very happy with their piston weapons. This is not meant as a knock on the piston conversion systems out there, but as a philosophical dialogue focused the new physiological relationships applied to the M16/M4 platform through the introduction of an operating system which has traditionally been applied to receivers with rails for the bolt and/or carrier. I would rather see an entirely new weapon system designed for the piston from the ground up. I believe there several outfits currently working on this."]

Crane: What do you think about fluting the chamber? What’s your opinion on that?

Noveske: I don’t know. I’m not 100% German. I’m only 25% German, so I only understand fluted chambers about 25%.

[At this point, we discuss chamber fluting a bit]
Noveske: A gas-operated firearm needs an extractor. A blowback or delayed-blowback firearm may not need an extractor. Sometimes they’re put on for good measure, but it’s not always necessary, because the case is pushing the bolt back, the bolt is not pulling the case out.
[Some more conversation about fluted chambers, of which Noveske is not a fan.]
Noveske: I like havin’ a gas seal around the neck [as opposed to a fluted chamber], and I also don’t care for blowback [or delayed-blowback] rifles.

Crane: Right, o.k., now you’re double-chrome-lining your barrels, or some of your barrels, not the stainless steel barrels, but the…

Noveske: The N4 Light Carbine and N4 Light Recce barrels.

Crane: Light Carbine barrels. You’re double chromin’ ‘em, and obviously, you must be getting a pretty nice even chrome job on there.

Noveske: Yes. I have a tolerance that is equal to a match-grade barrel.

 

[jerkface11]

The piston systems add nothing but complexity to the gun.

 

[mp5a3]

Hmmm, no opinion on Mr. Noveske's interview..

I still wonder why piston guns go for more. I mean, it's a tube with a rod and spring. They've been making them since the Model T was around. There may be $15 more in parts.

Also, I never liked the AR as a piston gun, I mean look at the AK, that thing has a big, beefy piston.

 

[Zak Smith]

The DI AR-15 parts are ubiquitous but GP parts are specialized. Hence less economy of scale and they have to recoup R&D costs.

 

[ArmedBear]

Piggybacking on what Zak said, I think a more interesting question is this:

Does anyone see a possibility that a standard will emerge?

 

[cameron.personal]

Hmmm, no opinion on Mr. Noveske's interview..

Thanks for posting that, and I am pleased to see the Mr. Noveske agrees with me.

Cameron

 

[MCMXI]

Hmmm, no opinion on Mr. Noveske's interview..

Are you kidding!! Do you honestly think that Mr. Noveske is objective (although he does sound like a "good" guy)? When asked "Do you have any plans to do a piston gun?" he replies "We have piston plans, but we don’t have any plans of putting it in production, because it’s…I don’t think it’s necessary."

HUH!! He has piston plans (WHY if he doesn't think it's necessary) but he's not going to generate any money by selling them (double HUH!!). What a contradiction. If he isn't going to sell piston guns to make money, why would he say anything that could potentially reduce his DGI sales?

 

[MCMXI]

By the way, did Mr. Noveske test a POF GP AR that has a two position gas plug (Normal and Suppressed) ... I doubt it?! Suppressors aren't legal where I live so I'm not able to form my own conclusions.

 

[Zak Smith]

Why would that matter? The majority of the gas when shooting suppressed comes back through the chamber. In any case, he has had his switchable gas block for DI AR's on the market for quite some time.

 

[MCMXI]

However, in a dedicated suppressed upper, I believe they [GPs] do have benefits.

So what benefits are you referring too? Heat, carbon fouling ... what? Seems like the only variables left are heat and lubrication but you mentioned firing hundreds or thousands of rounds without issue from your suppressed DGI AR.

Why would that matter? The majority of the gas when shooting suppressed comes back through the chamber. In any case, he has had his switchable gas block for DI AR's on the market for quite some time.

Define "majority"? Do you mean the majority of the gas that would have come back through the gas tube or do you mean something else? My understanding of the POF reversible gas plug is that it has a smaller port on the "S" side to reduce the amount of gas/velocity acting on the piston ... nothing more. I have no idea how it affects fouling during suppressed fire ... maybe it does, maybe it doesn't. It's purely academic for me at this point anyway.

Does Noveske's "switchable" gas block change the amount/velocity of the gas coming back down the gas tube? Does he market it for suppressed use?

 

[taliv]

1858, the benefit of GP is consistency/reliability when going back and forth between suppressed and unsuppressed on a very short barrel (edit: and not having to tune with H, H2/3 buffers or heavy springs, heavier carriers, etc)