Can ya'll explain the pro's & con's of these two action types?

piston runs cleaner and cooler

impingement works fine for 99% of us and is cheaper. I own/have owned 223, 260, 308, and 300 SAUM ARs. All were impingement, never ever malfuctioned or were cleaned very often. None were full auto, burst mode, or ripped off 20-100 rounds as fast as I could pull the trigger.

The AK 47 uses a gas tube system. What is the most reliable military semi-auto battle rifle ?

Gas tube is "tactical cool" so it must be better, but the tubes need to be cleaned too.

With the exception of the cabon fiber 223s, (impingement) they are all too heavy, good for killing people and questionable (compared to alternatives) as a hunting rifle.

4.5 pound 223 with lexan magazine, w/o scope, light & laser. Shoots minute of raghead out to 300. That's all it is for.

When did you have to clean a gas tube? I"m totally flabbergasted at that? I"ve run so many barrels through AR uppers and have only changed one tube due to wear on the end where it seals into the carrier group. At least read my comment on changing barrels to say that I"ve had at least up to 6-7 barrels on some of my uppers so far.... and thats a life span of anywhere from 3500 or so to over 12K rounds on one barrel.

Where did you read that gas tubes are tactical cool and WTF is tactical cool anyway really? Gas tubes are how it was designed and have worked for so long without flaws are the reason they are around vs piston.

A buddy just bought a piston gun. Just like I thought, so far its reliable, even though its a ruger, but its accuracy so far just ain't what a GOOD AR is capable of.

Bottom line for me, I trust my life to non piston guns.

Isn't Interthem Oldman's newest reincarnation? This place is going to the dogs again. Maybe Rick will ban him again soon.

I have been shooting DI guns since 1978 not once in over 30 years has one failed to fire or perform as expected. I have fired one for well over 700 rounds without it being cleaned.

Oh my gawd, I have never ever cleaned the gas tube on my ARs! Does that mean I'm going to have issues with them?

One needs to also remember that piston designs are all different and proprietary, and so are the bolt carriers for these piston guns. Going piston means you kiss good bye to two things: raw accuracy and parts interchangability. If these two things are not a concern for you, then a piston may well suit your needs.

Oh and there is the problem of carrier tilt in piston ARs. So maybe three things.

Because they have inherent flaws or you just have not owned any? I am a novice trying to determine if I even want to own a black gun. I have been looking at the IWRC R.E.P.R.. It's a 308 piston gun.

I have fired several AR's of the impingement design and they were incredibly accurate at 100 yards, open sighted, even with me behind them.

Consider the fact that while “technically” on paper, the gas piston designs “should” be better, they are NOT proven in military service. Any student of military arms can tell you that most every military rifle “should” have worked right off the bat, but most every major military rifle ever made has had issues once they were pressed into military service; issues no one foresaw before military service. And those issues are almost always NOT issues of design, but of materials and manufacture. There have been oodles of changes in materials and manufacturing techniques to the M16 series rifles, but almost no overall design changes (functionally). The M14 had some significant heat treating and metallurgical issues. Same as the FAL. The M1 Garand had minor design related issues that became serious functioning issues. The G3 had several teething problems. Yet all of these rifles went on to have extremely distinguished service careers.

So while people may be oh-so proud of their gas piston AR’s, consider two things:

The AR was NOT designed for a piston system. Any piston system AR is a work-around. Consider just one little thing, the gas piston rod pushes against an area that was never intended to drive the bolt. The AR bolt was DESIGNED to be propelled from within, not a-top of.
No gas piston AR has significant in the field time. The H&K 416 has had some limited time in the field with special ops. But that’s limited time, and special ops. To me it’s not proven until it’s years in the field, in the hands of poorly trained grunts.

I don't have piston guns because its a fix to a non existant problem. I don't buy into crap like that.

As to accuracy, it may well be that my demands of an AR accuracy wise could well be more than the average folks, but I have yet to see anyone that has a piston AR get .5 or less MOA out of it at distance. 100 yards is not distance.

I can generallly shoot groups in the 1/2- 5/8 inch range with a non piston AR off bags and irons at 100 yards. Or with a sling from prone.

If you want piston, then go for it. But there is no need. And as noted, the AR was never designed as a piston platform so only time will tell if it works out in the platform.

I'd make the decision if you even want an AR first, then decide which one and what parts based on the use. If you aren't sure you want one yet, then you are way ahead of yourself starting to differentiate IMHO.

And there are many reasons to have and not to have.... and just because is good enough for me.

Just go buy a cheap $1000 Colt 6920 in 5.56, 1000 rounds of XM193, 5 Pmags, and go shoot it all, then clean your rifle. This will teach you something and at the same time you will have a worthwhile gun in your possession that you can sell for near what you paid for it if you dont want it. Or you can just go visit different websites until you get the answer you want to hear based on an internet experts advice who hasn't pulled a trigger on any of his shiny new black rifles in 5 years. Those pictures of those shiny black rifles with every optic and accessory on them known to man just make me sad about my poor outfits.

the pros of direct impingment systems, is that they work, and work well.

The cons of pistons systems is that they are expensive, and really add nothing to the accuracy or reliability of the DI system.