DI vs. Piston

[fast97rs]

OK,

I'm a bit of a noob. I keep seeing all the new piston AR's coming out and am wondering..... whats the big deal? Whats the trade off?

The only thing I could think of that would bias me to buy a piston AR upper is that the bolt may last longer as it wouldn't get as hot, but in general I feel that this is a fix for a problem that doesn't exist.


Maybee its just my ignorance when it comes to how firing systems function, but why would the piston be that much cleaner, and thus more reliable, then a DI system? Wouldn't the piston be fouled by the same gases that fouls the bolt in a DI gun and need just as much cleaning?

How is accuracy out of these piston guns?

Basically what are the tradeoffs?


Jorgy

[Stickman]

Increased or sharper felt recoil with most piston weapons I've used.

Pistons tend to be cleaner, but still get dirty, especially with using a can.

Piston manufacturers use their own sytems, which means you can't grab part off another weapon unless its the same make. Standard AR15/ M16s are a dime a dozen, and parts supply isn't an issue for most of us.

Piston weapons tend to run cooler.



These are a few basics, and other people can probably throw in a much longer list.

[ZOMBIE101]

& I was just about to jump into the piston bandwagon....Guess not afterall:rolleyes:

[C4IGrant]

OK,

I'm a bit of a noob. I keep seeing all the new piston AR's coming out and am wondering..... whats the big deal? Whats the trade off?

The only thing I could think of that would bias me to buy a piston AR upper is that the bolt may last longer as it wouldn't get as hot, but in general I feel that this is a fix for a problem that doesn't exist.


Maybee its just my ignorance when it comes to how firing systems function, but why would the piston be that much cleaner, and thus more reliable, then a DI system? Wouldn't the piston be fouled by the same gases that fouls the bolt in a DI gun and need just as much cleaning?

How is accuracy out of these piston guns?

Basically what are the tradeoffs?


Jorgy


Stick covered most of the differences. You also tend to see vertical stringing with piston guns.

Having talked to Larry Vickers about this subject, he feels that a piston system belongs in a weapon that meets one of the below specs:

1. Barrel length 14.5" or below.
2. Full auto fire
3. SBR + suppressor

If you are shooting a 16" weapon (especially one with a middy gas system), then a piston system is most likely not needed and would do nothing for you.



C4

[John_Wayne777]

OK,

I'm a bit of a noob. I keep seeing all the new piston AR's coming out and am wondering..... whats the big deal? Whats the trade off?


If you need to run:

A. A short barreled config (shorter than the M4 configuration)
B. A suppressor
C. More full-auto fire

Then something like the forthcoming H&K 416 is worth a look.

If not, you're probably just fine with a DI AR weapon.

If you've got money to burn, then 1. send a bunch to me and 2. buy whatever tickles your fancy.




The only thing I could think of that would bias me to buy a piston AR upper is that the bolt may last longer as it wouldn't get as hot, but in general I feel that this is a fix for a problem that doesn't exist.


The problems exist...perhaps not for you and the way you use the weapon, but they do exist. If I was a SWAT ninja who needed a weapon with a 10" barrel I would certainly be giving the piston designs a long hard look. From what I've observed in training the shorty AR configs are the most problematic of all the AR designs. A piston driven weapon might well be worth the extra expense and headache to get a bit more reliability in those ultra-short configs.

Now since I'm not a SWAT ninja, I don't really need a weapon with that short of an OAL, thus I don't have one....so I won't really see much of an upgrade in reliability by buying a piston design.

It's likely you are in the same boat.