The DI design is standardized and works fine. There are at least a half dozen successful piston designs on the market now and not a whiff of one being adopted by the .mil and becoming standardized.

The downsides to a gas system are many....for one it adds around a pound to the gun. Parts, as you mentioned, may be proprietary and hard to source. The company that makes them may go out of business and parts will be impossible to source.

But some people want a piston system for whatever reason. I just don't think reliability is a realistic criteria. As the DI system is proven to be a reliable system.

 

The DI design is standardized and works fine. There are at least a half dozen successful piston designs on the market now and not a whiff of one being adopted by the .mil and becoming standardized..

The HK416 is a piston design and I believe it has been adopted by some parts of the US military (along with some foreign forces).

Both HK and LWRC make outstanding piston driven AR’s. Piston AR’s do run much cleaner in the receiver than DI guns, which can save you some significant cleaning time. I own all LWRC made piston AR’s and can attest that the build quality is outstanding for all their components (not just the piston parts). Based on my experience and extensive research, my opinion is that a quality piston driven AR (built by companies like HK or LWRC) , will be more reliable and outlast a similar DI gun under harsh conditions over the lifetime of the gun.

I’ve shot a lot of different piston AR’s over the past 15 years, made by a variety of manufactures, and there is a fair amount of poorly designed or retro-fitted stuff out there that is NOT quality and not better than a DI AR. That was more true 10-15 years ago when piston AR’s first became more popular, but it’s gotten much better as designs improved and gun makers came out with purpose designed and built piston rifles and not attempting to retrofit DI designs.

That being said there is nothing wrong with DI AR’s for most users and unless you’re a real gun geek, with cash to spare, there is no reason for most people to spend the extra money for a piston AR. I used the Army issued M4 on active duty, in some nasty environments (Bosnia and the Middle East) and never had an issue with it when properly cleaned and maintained.

 

Your AR15 "friend" has limited knowledge. I see more piston guns go down than DI guns at 3Gun matches, and the vast majority are running DI guns. You are adding weight, and another linkage. In the simplest terms, the gas piston is a more complicated system.

The only real reasons to run a gas piston system is if you run really dirty ammo and or a suppressor. Even then, the benefits are marginal.

There are a lot of gas piston weapons in the market, many preceding the AR15. But from an engineering perspective, the AR15 DI system is an upgrade from the gas piston system.

 

no expert on the ar here, The general attitude I hear is that if ya clean every 2k rounds or so,either system works well for civilians.

 

Read an article called "filthy fourteen" and you will see what the true facts are and how durable the D.I. system is.

 

I'm sure there's has been addressed before, but looking for current thoughts and opinions...

So I'm thinking of picking up a used Huldra Mark IV in good shape. It's the bare-bones model and it comes with a Gas Piston. I've got a lot of firearm experience, but the AR platform has never been a part of my life. My knowledge of the AR is exceptionally limited.

One of my AR15 friends says the gas piston will be absolutely unstoppable and will run forever.

The other says is new technology with a proprietary bolt design and I'm asking for trouble because it's not a tried, true and proven design.

I'm not trying to start a flame war. I'm just trying to understand what I'm getting myself into.

Thank you for your help.

You want a gas piston gun? Get a gun that's designed from the bottom up as a gas piston gun.

Leave the AR the way it is.

 

There has never been an issue with the standard DI system. Some folks just like to get the new "better" thing. If I was going to get a piston AR, it would be one of the various long stroke systems. I think they eliminate some of the inherent piston issues. Since my DI gun runs just fine, I won't be "upgrading" anytime soon.

 

I have to side with the rest. A piston-operated AR is of no real benefit. More moving parts, more weight, and proprietary parts make it less appealing. DI ARs have been around for 57 years now and work just fine. I would never own a piston-operated AR myself. If you want a smaller piston-operated weapon, there is the AK and the TAVOR.

 

DI's shoot and shoot well.

When I first started to get interested in AR's was the beginning of the piston craze.
Big push about the limitations of DI's and how pistons would change the world.

Then many frequent and long time AR people started saying:dunno:, DI's are simpler, often lighter and just work.

I skipped the piston route and don't regret it at all.

 

Those that say a piston system is heaver and complicated don't know what they are talking about. Them stating such just shows how much they don't know about the system. I would also bet that they have never owned one or they would know how they work.

The only difference in a gas system and piston system is the gas tube is replaced with a rod and the gas block has been drilled out and the piston is put in. Well it really isn't a piston it is more like a valve. The rod is really the piston. Oh also you have to remove the gas rings from the bolt on the piston system.

If they picked up a piston system and it was heaver than the gas system it was because of a heaver barrel or hand guard. It wasn't because of the piston system. The difference in weight of a gas system and a piston system is the deference weight of the tube and the rod. That may be a couple of OZs.

Sig sells a piston system that a lot of military and police units use. Also the AK has a piston system. I think most people would say they are reliable. The piston system isn't a new system. It is just new to the AR and people don't like the things they know changed.

The biggest advantage to the system is it don't put hot gas in the chamber to make things work. So the system stays cooler and cleaner. In any system the cooler and cleaner you can keep a system the better. It makes for less friction on the parts. That is why we have filters and coolers in our cars.

I have and run both systems. If I planed to run a lot of ammo through a rifle I would want it to be a piston system. In a SHTF event I would want a piston system. They are easer on the bolt and other moving parts in the action because of not putting hot gas in the action. They are also very easy to clean.

Good luck with what ever you decide on. There is a lot of information on the AR, you could read about it for years.

 

The biggest advantage to the system is it don't put hot gas in the chamber to make things work.

I don't care who you are, that is funny stuff right there. I'd like to see the gunpowderless piston guns that have no hot gas in the chamber. :devildance:

 

Piston systems are generally heavier. No one is saying they weigh a ton more, but a solid steel rod does weigh several ounces more than a thin hollow tube. Hanging that weight out on top of the barrel makes it feel like even more.

Also, your argument is somewhat undone by the defensive attitude towards other posters. Not to mention the many misspellings.

 

Owning a Sig 516 myself, then comparing it to my brother's (a Master Sargent w/82nd) DI AR side by side, running a full 30 rd mag then comparing bolt temperatures and the ease of cleaning and cleanliness afterwards. I would take the piston ar every day and twice on Sunday. The few ounces of weight is nothing. Plus that little extra weight helps absorb more recoil over a DI ar. Not that a 5.56 ar recoils much to begin with.

 

Along with what has already been said, piston guns are usually more expensive. Sometimes much moreso.

 

Piston ARs are solutions in search of a problem. Pass.

 

Oh no, not this... not again...

 

Meh whatever heat and crud doesn't end up in the upper receiver, ends up in the piston system. 6 of 1, half dozen of the other, your scraping carbon off regardless. I never cared how hot the upper receiver got, just the barrel.

Looks like the OP is looking at a lower end piston rifle. You can get more rifle for the same money with a DI. If you have to have a piston AR spend the money on one of the better piston ARs like from PWS. They are not all the same.

 

Likes both !

 

Meh whatever heat and crud doesn't end up in the upper receiver, ends up in the piston system. 6 of 1, half dozen of the other, your scraping carbon off regardless. I never cared how hot the upper receiver got, just the barrel.

Looks like the OP is looking at a lower end piston rifle. You can get more rifle for the same money with a DI. If you have to have a piston AR spend the money on one of the better piston ARs like from PWS. They are not all the same.

Honestly, I'm not sure where this AR falls into the spectrum. It's a base model Huldra Arms Mark VI. I believe it's mostly a re-branded Adams Arms. Retail on it is around $1100, but I should be able to pick it up for around $700 in excellent condition.

 

Wishoot I paid a little over $600 for my Adams Arms upper. So that isn't a bad price at all if you can get the rifle for $700.

 

Lube a DI AR thoroughly with lithium grease. The grease captures most of the carbon and lets it get pushed aside and out of the way. Like this I shoot dirty ammo, and rarely ever need to clean my AR. No hiccups yet.

I used to think a piston was a good idea, but now I realize that it's just more moving parts that can fail, and more proprietary parts that aren't compatible with most of what's on the market.

 

In my opinion, if you're dumping enough "hot gas" into your upper receiver to cause a problem, you're probably going to destroy the barrel first and probably will burn your hand on the rail over the piston. From my standpoint here are the pros & cons for gas pistons.

Pro:
* It's cool, like an HK 416
* Less to clean inside the receiver

Con:
* Heavier
* More expensive
* Proprietary parts
* Extra weight
* Bolt carrier tilt

The proprietary parts is the con that keeps me from buying one. Same reason I won't buy/build a .308 AR variant.

 

I have owned a few piston guns........have only kept one.
That being a PWS Diablo MK 107. And it is on a pistol lower, so simply nothing more than a play toy

 

But they are a fun toy.

 

The amount of carbon on the piston is next to nothing. It just boils down to what you want and are willing to spend.

 

Thanks everyone.

 

Pretty much the same system the DI gun has the piston in the bolt carrier

 

I have both. My pistons are LWRC and HK and they are in 5.56 and 7.62. Sig copied the LWRC system and was sued.

I'm left handed so having the gas and debris blow in front of my face from most DI's is a negative. Also, the adjustable valve on a piston is a positive as I can switch from non ejecting (manual cycle) to still working even though it is very dirty. Since the HK416 is an issued weapon, I don't think parts availability is an issue. I can still get new parts for my HK91. The piston can run drier as not a much lubrication is necessary.

They are more expensive and heavier but I also shoot an M1 Garand and M14 NM. Also my SKS and AK are piston. They are heavier than the DI AR and historically have been very reliable under almost every condition they have been used.

I had an FN FNC and FN FAL which were pistons long ago.

I haven't had any problems with my DI's and pistons are just another flavor.

 

Anyone remember the thread by the guy that worked for the shooting range in Vegas? IIRC, they didn't have as great reliabity with piston systems compared to DI. Don't quote me on that though.