AR difference?

[jbcalhoun]

Ok, I would like a simple answer, if possible.

I understand the gas operation of an AR, but just how does the piston type work?

What are the advantages, if any, for the piston type?

Probably just a dumb question, everybody but me knows the answer.

Brad

 

[Texas1911]

The gas piston assembly replaces the gas rod running between the gas block and the bolt carrier. The gas from the gas block pushes onto the piston, converting the gas energy into mechanical energy. This energy is what is used to cycle the bolt via a pushrod.

Essentially it's like an AK47, Garand / M14, etc.

The benefits are cooler operation temps, less fouling and carbon, and a bump in reliability as a result. It's good for machine guns and people that run their kit hard, but for the range rat, it's not necessary.

 

[Sid]

At best, it helps with minimizing blow back from suppressed fire.

Otherwise, any top tier manufacturers' AR will be just as reliable with weight savings to boot. And you really don't have to clean a DI AR to a white glove standard.

 

[The_Hunter]

And you really don't have to clean a DI AR to a white glove standard.

you really don't have to clean a quality gas system gun to a white glove standard. With proper lube and a correct buffer a quality DI gun will run thousands of rounds reliability before it needs cleaning.

the above explanation of how the systems work is good. I would add a piston system is going to be heaver, more complicated, and typically less accurate

 

[M. Sage]

I'm going to dispute the "running cooler" thing. Next time I get my barrel smoking at the range I'm going to pop the bolt carrier out and get some temp readings with my IR thermometer.

Ok, I would like a simple answer, if possible.

I understand the gas operation of an AR, but just how does the piston type work?

What are the advantages, if any, for the piston type?

Probably just a dumb question, everybody but me knows the answer.

Brad

They take the piston out of the bolt, make it smaller and put it in a tube above the barrel (where the gas tube typically goes) with short rod that pushes the bolt back. There isn't really any difference in how they work (they're technically both short-stroke piston systems), it's only a matter of where the parts go.

Save your money - get a "DI" gun. They run just fine. I'm up to almost 500 rounds of cheap Russian crap ammo in my M4 without cleaning or failure. The key is learning how to lube an AR properly, and no the military does not do it properly. Here's the right way. A friend of mine started doing this before I even got my first AR, and several other people I know are doing it, all with excellent results. It's actually fixed some rifles that were unreliable problem guns.

At best, it helps with minimizing blow back from suppressed fire.

Otherwise, any top tier manufacturers' AR will be just as reliable with weight savings to boot. And you really don't have to clean a DI AR to a white glove standard.

It does help to reduce cycle speed with a suppressor, and reduce gas port erosion. But yeah, it's not terribly useful. It's also got a negative effect on accuracy and makes maintenance harder.

 

[jsimmons]

The key is learning how to lube an AR properly, and no the military does not do it properly. Here's the right way. A friend of mine started doing this before I even got my first AR, and several other people I know are doing it, all with excellent results. It's actually fixed some rifles that were unreliable problem guns.

It does help to reduce cycle speed with a suppressor, and reduce gas port erosion. But yeah, it's not terribly useful. It's also got a negative effect on accuracy and makes maintenance harder.

That's how I lube, too. I still clean/re-lube after every range visit though, and I use Valvoline Dura Lube - I got a big can for $5, and most of what I've used was when I completely disassembled my 1911, covered all the parts in grease, and baked them in the oven for a few hours (I did that a few years ago, and I don't have any problems with rust on that pistol). For my AR, I use q-tips to apply the grease.

I also wear *powderless* nitrile gloves.

 

[jbcalhoun]

I would add a piston system is going to be heaver, more complicated, and typically less accurate

Thanks guys. With all the hype, I'm pleased to know about the weight and the accuracy part. I can keep my AR's clean, no problem there!

Brad