View Full Version : New to AR looking for input DI or Piston

December 22, 2010, 11:07 PM
Ok folks asking for opinions or advice: I am looking to buy an AR in January.

I am very familiar with pistols and shotguns, but am now looking for an AR in5.56 Nato/.223...

Now what is reccomended these days? Gas DI or Piston?

I have been looking at Daniel Defense, Stag, S&W M&P 15, Rock River.

Any suggestions/tips are greatly appreciated.

Thanks, Mike

December 23, 2010, 09:46 AM
I would add LMT to your list of AR manufacturers, they'll sell you a complete lower and a complete upper separately and then you can pin them together and get around the 11% federal excise tax and put your price point right around the DD rifle.

Seriously though, it's a trap! You're looking to buy an expensive rifle that needs expensive accessories and is specifically designed to blast through expensive ammo quickly. Don't do it. Convinced?

Iron Man
December 23, 2010, 10:16 AM
Buy a Sig 522! Shoots great, shoots cheap. Or, get the S&W M&P .22 version. Super nice gun!

Willie Lowman
December 24, 2010, 01:58 PM
I have owned 4 AR-15s through the last ten years. A Colt HBarII, a Wilson Combat, and 2 RRA.

For everything you will read about how Colts suck and/or they are the greatest thing ever etc... I still have mine. Two of my friends shoot Colts. I think RRA has a better factory trigger but Colt has better fit and finish...

I sold the Wilson Combat for a number of reasons. It shot well but I found that all the tacticool features it had were basically useless. I sold one of the RRA rifles to fund a 22-250 build.

As for the reliability of the direct gas system; I normally shoot 200 to 500 rounds of PMC through the course of a day in my RRA mid length without trouble of any kind. My Colt has seen over 10,000 rounds having only broken one extractor and having the trigger assembly replaced with an aftermarket one a few years back.

Depending on preference of barrel length, I would recommend http://www.rockriverarms.com/index.cfm?fuseaction=category.display&category_id=219

Or http://www.rockriverarms.com/index.cfm?fuseaction=category.display&category_id=225

December 24, 2010, 01:59 PM
Get a direct impingement system. It runs a little dirtier than gas piston, but parts are "universal" and it is lighter.


December 24, 2010, 02:02 PM
I have no problem with the DI system and I''ve been shooting M16/ARs since 1967.

The Piston is a Solution to a Non-Existent problem, but if it makes you feel warm and fuzzy, go for it.

December 24, 2010, 02:22 PM
The DI system is a proven performer. I shot ARs for about 30 years and never had a problem with DI.
That said, if you plan to run a sound suppressor you may want to check into a Piston driven system.
I run a sound suppressor and chose an old, Piston driven Daewoo K2 over a DI AR for just that reason.


Good luck


December 24, 2010, 02:59 PM
When I purchased my AR six months ago, I went with DI for the same reasons that Jimro stated. Parts are far more available. Also, because there's no 'standard' piston, you might be looking at more down time if something is wrong with the rifle because you had to order directly from the manufacturer as opposed to making a quick run to the local gun store.

December 24, 2010, 03:44 PM
The Piston is a Solution to a Non-Existent problem, but if it makes you feel warm and fuzzy, go for it.

Kraig pretty much summed this one up...^^

December 24, 2010, 04:39 PM
I also have to chime in for DI. Works fine, very reliable, standard replacement parts available from countless sources and less expensive.

Of the brands you mentioned I like Daniel Defense. BCM is a great choice too. Like mentioned above you can build/buy a lower receiver and an upper receiver and pin them together for a decent savings (probably $100 or more). You don't get the comprehensive factory warranty though. I did this for my first AR and now doing it again with the incredible sale smartgunner.com is having on Daniel Defense uppers. I will pin it on a S&W lower waiting for it.

December 24, 2010, 08:37 PM
Another vote for a DI gun
BCM, DD, S&W, LMT, Colt, Larue, Noveske

Willie Lowman
December 24, 2010, 11:09 PM
Here is my RRA With EOtech http://farm5.static.flickr.com/4100/4805303924_71cb7946a7_b.jpg

December 24, 2010, 11:14 PM
Will you clean your rifle.... ever? Or at least every case of ammo or so?

Yes? The DI will be just fine.

December 24, 2010, 11:25 PM
Gas DI or Piston



December 24, 2010, 11:28 PM
+1 or +5 or whatever we're up to for the DI gas system. The piston isn't necessary, and most of the conversions out there create at least as many problems as anything they solve.

December 24, 2010, 11:39 PM
Through the course of having double digits of ARs I've of course considered the piston, but I've never been able to convince myself that it's advantageous. DIs do just fine.

December 24, 2010, 11:41 PM
Another vote here for the DI. I carried a standard issue M16 for four years and beat the living **** out of it. Dragged it through mud and definately treated it worse than I would my own. It jammed on me once. That was during an obstacle course with so much mud caked in the weapon and shooting hundreds of blanks I honestly don't see how any weapon would have fired. l just recently bought a new ar-15. I didn't even think about it. DI for me, and I would trust my life with it.

December 25, 2010, 05:59 AM
I own both an RRA DI and a Stag Arms piston rifle. I like them both and intend on keeping them for a long time. The piston gun is easier to keep clean and has worked without a hitch since I purchased it. My RRA has the national match trigger so I tend to be moe accurate with it over my Stag. It does get dirty though and re

December 25, 2010, 06:03 AM
The piston gun will send less carbon back to the bolt carrier and bolt, that's about it. Unless its an HK416 which is really a different gun in an AR's body (and probably not something you even considered buying), a piston AR will be less reliable for a lot of reasons (carrier tilt etc).

December 25, 2010, 06:19 AM
im asking a similar question in a different thread.

and as i posted, IMO mind you... there is no real advantage gain one over the other.

DI is dirtier than the Piston but if you keep your stuff clean then it a non-issue. i have cleaned an AR that was SOOO gummed up with carbon, and IMO too much lubrication, that you could not charge the bolt without forcing it to the degree that made me cringe with the possibilities of things breaking

i just want to try out the piston for poops-and-giggles, as something new, and im looking retro-fit kit since i dont want another AR.

though the piston does have the advantage the suppressor crowd and the clean factor, the DI has the advantage of SUPER easy to find parts, cost, and a proven operating system on the AR platform, while the piston is still somewhat of a new trick for a getting to be old dog

my point... whats better or recommended? i would say for the easy of parts, cost, and PROVEN operation i would go DI,....but i dont have any real time experience with the piston so.... *shrugs*

December 25, 2010, 09:17 AM
Go with DI and check what warranty you get with your new rifle. Some offer three years others are lifetime.

December 25, 2010, 06:54 PM
It's really up to you. I own more piston ARs than I do DI. My go to though is a KAC SR15. It's just lighter so at day long carbine courses it makes it somewhat easier.

There really isn't a right answer. Both will serve you well. For those that say it's more parts do the math.

Op rod
Maybe a spring


Gas tube
Gas ring
Gas ring
Gas ring

I would bet that the gas rings or tube will go bad before a op rod, piston or plug.

December 26, 2010, 03:53 AM
Globalsmack that is nothing more than conjecture.

If you buy a proper m16/m4 upper with m16 bcg and oil it you'll never have problems with a DI gun. Pistons add extra weight, extra proprietary and expensive parts, and don't fix anything. Your barrel will be useless before the carbon fouling in a DI gun can start causing any problems. Piston AR15s exist because some complete fool attributed the reliability of the AK design to its piston operation and not the fact that it's crudely made with very high tolerances between parts.

December 26, 2010, 04:38 AM
If you buy a proper m16/m4 upper with m16 bcg and oil it you'll never have problems with a DI gun....Your barrel will be useless before the carbon fouling in a DI gun can start causing any problems....

not true at all especially the second statement i quoted... i've had to clean AR's that were so fouled with carbon you couldn't cylce the action with out major force and the bolt would close upon releasing the charging handle. it took 6 hours to clean... 6 HOURS! then add in the corrosion that was eatting the bolt. broken gas rings suck.

not advocating DI or Piston either way, just saying

EDIT: i should say that either system NEEDS to be maintained properly and cleaned correctly

December 26, 2010, 09:01 AM
You see this is what's laughable. Some fool must of thought the M14 needed to be updated and the stoner rifle was born as something new. Why is it ok to say if you clean and maintain your DI gun it will last forever yet somehow the Piston isn't held to the same standard?

When you buy a high end piston you end up with a lot for the money. Chrome or np3 coated bolts and carriers, excellent barrel options compared to M4 spec, upgraded trigger groups, ect.

Mil spec is the lowest common ground the Gov't will accept not the high end standard for the market place. There is better stuff on the market today. Piston or not it a good time to be a buyer.

December 26, 2010, 10:23 AM
Now what is reccomended these days? Gas DI or Piston?

Only Idiots and Piston Salesmen are suggesting Pistons. Even Ruger's wonder piston is starting to show the typical flaws of the piston design already.

There isn't ONE trouble free piston gun out there period.... not even HKs stupid gun.