Quote from: Cougar8045 on January 06, 2012, 07:52:39 PM

A thousand rounds without a break for cleaning sounds like a hell of a firefight to me, even by military standards, although I could be wrong about that.  That's 33 magazines' worth of ammo, plus some change.  I'm thinking you'll have either won the fight or been killed by the time you spend that much ammo.  If there's been over a thousand rounds downrange with no winner, I'm going to propose we call it a draw and everybody go home!  lol  (Long story short, 1k sounds plenty good to me!)

nope, its was range time followed by two hdf shoots...but i know my Daniel Defense M4 can handle it...

I didn't word that very well.  I meant to illustrate that your 1000-round "torture test" far exceeds the actual round count without an opportunity for a quick and dirty field strip/clean that a body would ever reasonably (or even unreasonably) expect to see, even in an end-of-the-world-as-we-know-it scenario.  Which is why I'm perfectly comfortable going with DI.

I've shot both DI and GP.  I own a a gas piston one.  The first DI's I shot were military issue one back when I was in highschool and went to JROTC spring camp up here at Schfield.  Got to shoot them on semi and 3-round burst.  I loved those rifles.  Later I shot my friends Stag Arms and Colt AR's and again solid rifles.  So why did I buy a gas piston?  Mostly because that is what fit my girlfriend the best.  I bought a PWS MK116.  I listened to Tony's (Gun Source) spiel about DI vs GP.  He pushes PWS big time, but I wasn't sold right off the back.  I spent a lot of time reading and then brought my girlfriend down to see the rifle.  She loved it.  I like because of the ease of cleaning and it is just as accurate as my friends DI rifles if not more so.  The best part of the gas system is the lessened felt recoil.  My gas piston is a solid performer with very little recoil, it kicks like a .22.  The other consideration is looking at what SpecOps guys are using.  Reports state that SEAL Team 6 used gas piston HK416 in their raid on Osama's compound. But which is better for SHTF time it would be the DI.  Less moving parts and easier to maintain and repair if need be.

This a link to the snipershide forum which help me to decide if a gas piston PWS was something worth considering.

http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=2202139

HK propaganda showing why gas piston is better than direct impingement.



Overall I think it boils down to what you want.  My 6.5 Grendel rifle I'm building is DI and I have no problem with that.

Quote from: vooduchikn on January 06, 2012, 08:07:57 PM

Quote from: Cougar8045 on January 06, 2012, 07:52:39 PM

A thousand rounds without a break for cleaning sounds like a hell of a firefight to me, even by military standards, although I could be wrong about that.  That's 33 magazines' worth of ammo, plus some change.  I'm thinking you'll have either won the fight or been killed by the time you spend that much ammo.  If there's been over a thousand rounds downrange with no winner, I'm going to propose we call it a draw and everybody go home!  lol  (Long story short, 1k sounds plenty good to me!)

nope, its was range time followed by two hdf shoots...but i know my Daniel Defense M4 can handle it...

I didn't word that very well.  I meant to illustrate that your 1000-round "torture test" far exceeds the actual round count without an opportunity for a quick and dirty field strip/clean that a body would ever reasonably (or even unreasonably) expect to see, even in an end-of-the-world-as-we-know-it scenario.  Which is why I'm perfectly comfortable going with DI.

Back last year, 3 of us were at SRGC.  My friend brought his LWRC rifle.  He ended up putting some 800 rounds through his gun.  Total time was a bit less than 4 hours.  It was a rifle & magazine break in-test.  All semi auto.........and yes the rifle was cooking.  No issues with the LWRC.  No cleaning.  It worked.  That said, I'm quite sure if he had a good quality DI gun, it would have been fine also.  There was a Youtube vid some guy had posted when this issue came up about AK vs AR reliability.  Anyhow the vid shows 30 round mag dump after 30 round mag dump on full auto until the AR's furniture caught on fire.  It was crazy.  Anyhow if I ever come across the vid again I'll post it.

I've shot both DI and GP.  I own a a gas piston one.  The first DI's I shot were military issue one back when I was in highschool and went to JROTC spring camp up here at Schfield.  Got to shoot them on semi and 3-round burst.  I loved those rifles.  Later I shot my friends Stag Arms and Colt AR's and again solid rifles.  So why did I buy a gas piston?  Mostly because that is what fit my girlfriend the best.  I bought a PWS MK116.  I listened to Tony's (Gun Source) spiel about DI vs GP.  He pushes PWS big time, but I wasn't sold right off the back.  I spent a lot of time reading and then brought my girlfriend down to see the rifle.  She loved it.  I like because of the ease of cleaning and it is just as accurate as my friends DI rifles if not more so.  The best part of the gas system is the lessened felt recoil. ..................

I like the weight on the PWS.  If it isn't the lightest piston out there, it has to be close.  What I don't like is the way the op rod is captured on the bolt carrier.  It's so light I'm afraid that I would accidentally bend that rod when I was cleaning the rifle.

I like the weight on the PWS.  If it isn't the lightest piston out there, it has to be close.  What I don't like is the way the op rod is captured on the bolt carrier.  It's so light I'm afraid that I would accidentally bend that rod when I was cleaning the rifle.

I'm 110% with you on both points.  The weight of the rifle inlcuding holosight is even easy for my rather petite gf to shoulder and fire comfortably.  In fact she loves shooting it.  And yes that whole assembly thing is funky.  The first time I cleaned it on my own it took me almost half in hour to get the charging handle bolt carrier group back in.   Since then I've gotten used to it.

I find it strange that so many people are citing weight as a disadvantage to the piston.  The gas chamber is smaller than for DI, so there's a weight savings there, and the pistons themselves are pretty darned light.  It can't be a difference of more than a couple of grams!

As far as reliability, I think there are plenty of examples out there showing pretty conclusively that both systems are capable of extended continuous operation in less-than-ideal circumstances. 

As far as accuracy, I'm just not buying that there's much difference.  Slo-mo images showing one barrel whipping more than another probably have more to do with the specific barrel than the size of the gas tap. 

As far as recoil, it seem to me that the piston system, having more mass to be moved, would eat up kinetic energy that a DI system would turn into recoil.  However, given my earlier comment about the light weight of the pistons, it would probably be a negligible gain.

Cleaning?  Sure you have more tube to clean on a DI, but cleaning the seared-on crud from a gas piston ain't no picnic.

In short, as far as I can tell, the only reason to prefer one system to another is that you've chosen to do so! 

I find it strange that so many people are citing weight as a disadvantage to the piston.  The gas chamber is smaller than for DI, so there's a weight savings there, and the pistons themselves are pretty darned light.  It can't be a difference of more than a couple of grams!

As far as reliability, I think there are plenty of examples out there showing pretty conclusively that both systems are capable of extended continuous operation in less-than-ideal circumstances. 

As far as accuracy, I'm just not buying that there's much difference.  Slo-mo images showing one barrel whipping more than another probably have more to do with the specific barrel than the size of the gas tap. 

As far as recoil, it seem to me that the piston system, having more mass to be moved, would eat up kinetic energy that a DI system would turn into recoil.  However, given my earlier comment about the light weight of the pistons, it would probably be a negligible gain.

Cleaning?  Sure you have more tube to clean on a DI, but cleaning the seared-on crud from a gas piston ain't no picnic.

In short, as far as I can tell, the only reason to prefer one system to another is that you've chosen to do so! 

Yeah Yeah, what Tom_G  said

There is already a piston in the DI design.
How about a shoot out?? DI vs. gas piston" rifle at the 600 yard line. Jan 27or 28at Puuloa Range.

There is already a piston in the DI design

Well, technically, sure.  And there are two pistons in the piston design!

OK guys, here's the vid:


Lost count of the mags, but you're getting up near 30 30RND mag dumps before the gas tube is history.

Daaaaammmmmnnnn!! That's pretty funny and sad at the same time.

Anybody have a pigtail gas tube?

Daaaaammmmmnnnn!! That's pretty funny and sad at the same time.

Wish I had a budget for ammo like that guy...........

Quote from: DonRow on January 10, 2012, 08:19:20 AM

Daaaaammmmmnnnn!! That's pretty funny and sad at the same time.

Wish I had a budget for ammo like that guy...........

Wish I had that guy's whole gun budget!  Gas tube---effed.  Barrel---effed.  Everything else---maybe effed.     Cool demonstration, though.  Reposted to my facebook for all the AR naysayers.

Quote from: robtmc on January 10, 2012, 11:22:35 AM

Quote from: DonRow on January 10, 2012, 08:19:20 AM

Daaaaammmmmnnnn!! That's pretty funny and sad at the same time.

Wish I had a budget for ammo like that guy...........

Wish I had that guy's whole gun budget!  Gas tube---effed.  Barrel---effed.  Everything else---maybe effed.     Cool demonstration, though.  Reposted to my facebook for all the AR naysayers.

So long as the NFA parts are OK, it's a (relatively) cheap repair job.

There is already a piston in the DI design.
How about a shoot out?? DI vs. gas piston" rifle at the 600 yard line. Jan 27or 28at Puuloa Range.

The next Puuloa Club shoot is 21-22 Jan. I don't think you'll get any takers from Team Gas Piston. National Match style shooting is too strenuous for most folks.

ohhh 600 yards. Reach out and touch someone!

Puuloa Rifle and Pistol Club had their annual membership meeting. By popular vote, the next practice match is moved to 28-29 Jan. Team Gas Piston has another week to figure out if they will be able to hit paper at 600 yards.

For SRGC members looks like KR-3 will be available near the end of January.  Long long range.  No paper either, but it's an interesting venue to shoot at.  Very humbling.

Cool, I figured someone asked this here already.  Thinking of picking up an AR so this will help me pick which.

Cool, I figured someone asked this here already.  Thinking of picking up an AR so this will help me pick which.

So you're gonna pick up both? The question is which first.... I'm a AK guy, so my first was a piston driven AR... I don't have it any more but I think I'm gonna renew my permit tomorrow and build a DI sometime in the near future in coyote tan..... Dexter keeps pressuring me and I'm ok with it....