# Gas piston or Gas tube



## Quietstorm3155 (Nov 8, 2008)

I want to knowif any of you guys have tried the LWRC rifles with the gas piston system... (attch Video)  Or have you tried any of the other Gas piston rifles that are competeing with the AR15/M4 gas tube systems?  Below is also an OLD thread talking briefly about a test which was to compare these diff operating systems but I have not heard anymore.  So who has used the Gas piston system and how do you like/dislike it?

[ame="http://www.youtube.com/watch?v=N03LVJgUWdU"]YouTube - LWRC Gas piston rifles[/ame]



https://shadowspear.com/vb/showthread.php?t=6751&highlight=lwrc+rifle


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## AssadUSMC (Nov 8, 2008)

I haven't used the LWRC piston rifle, but I've used the HK 416 extensively.  I am a HUGE fan of piston over the gas tube.  Look at the FN FAL - probably the 2nd most successful battle rifle ever (after the AK).  Piston design....

The biggest advantages IMO are 1) maintenance/cleaning and 2) reduced recoil impulse (my subjective impression w/the 416).  I'm currently looking into purchasing an LWRC M6A2 - I need to stop by their shop (about 20 min from me) and have a chat.  If I find out anything new, I'll post it.


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## CAL (Nov 8, 2008)

It's funny you ask this now - I'm actually doing some research on the exact question because I'm looking to build a .308 on the AR platform.  So far, all signs are pointing to gas pistons.


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## 08steeda (Nov 8, 2008)

Can you covert an AR with a Gas Tube gun to use a Gas Piston?

I know probably a stupid question.


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## CAL (Nov 8, 2008)

08steeda said:


> Can you covert an AR with a Gas Tube gun to use a Gas Piston?
> 
> I know probably a stupid question.


Yes, but I don't know if it is worth the cost.


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## HOLLiS (Nov 8, 2008)

CAL said:


> Yes, but I don't know if it is worth the cost.



Other question is why?


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## CAL (Nov 8, 2008)

HOLLiS said:


> Other question is why?


Why is it not worth the cost or why get it done?


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## HOLLiS (Nov 8, 2008)

CAL said:


> Why is it not worth the cost or why get it done?



Both are good questions.


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## CAL (Nov 8, 2008)

HOLLiS said:


> Both are good questions.



Well, it may be worth the price to some folks so I'll leave that for the individual to decide but I'll talk a bit about why I think the GP system is better.

When the rifle is fired, the developing gases expand inside of the gas block much like a traditional DI system.  The expanding gases push against our short stroke piston which exerts pressure on the operating rod and thus gives momentum to the bolt carrier.  Once the piston itself has traveled 3/4", it expels any unused gas from a small vent in the bottom of the piston tube.  As the cycle of the action is already in progress, the piston moves to the back of its chamber awaiting the return of the operating rod to push it back into battery.

Here are a couple of animations that show the differences. (you can toggle between the HK for the GP and the AR for the DI by clicking the button in the bottom right corner)

http://www.armytimes.com/projects/flash/2007_02_20_carbine/

The primary benefit of going Gas Piston is a higher level of reliability by running a cleaner and cooler AR by moving the operation of the rifle from the upper receiver and bolt carrier to the front gas block using a small diameter short stroke piston which does not require constant cleaning or lubrication like a Standard DI (Direct Impingement) AR does in order to ensure functionality.

Also, you can have your AR cleaned in 5 minutes, vs. 30 minutes with a normal AR.

The Bolt Carrier and Charging handle are broken down the same way, and the Gas Piston Tube is located inside the Gas Block and is removed by pressing on the piston tube nut release button, turning the tube and removing it by pulling it out.

Then the tube is broken down very easily by removing the cross pin, removing the nut and taking the piston out of the tube.


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## 08steeda (Nov 8, 2008)

Plus based upon my research (today) and discussions the Gas Piston has a much lower recoil. Thus allowing a quicker followup shot and sight picture alignment. This would be the case for multiple targets in a highly Mobile environment.

Plus the lower heat saturation does not effect accuracy from the barrel etc heating and warping in high fire situations.

At least that is what I THINK I have learned.

The problem is that the conversion kit is 300 - 450 plus the labor by a reliable gun smith.

Probably better and more cost efficient just to get a Gas Piston rig to start with.


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## CAL (Nov 8, 2008)

08steeda said:


> Plus based upon my research (today) and discussions the Gas Piston has a much lower recoil.


Yep, I forgot about that.  With the Standard AR, the action is direct blow back into the upper receiver and the recoil is felt more in the upper receiver, closer to your face and shoulder.

The Gas Piston System uses a small diameter piston that only travels about 3/4" and meets the fixed op-rod, (which is affixed directly to the Bolt Carrier Group).  The Recoil is not as harsh since the action is now occurring in the gas block at the forward part of the rifle, plus the excess gas is blown out of the gas block.


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## Quietstorm3155 (Nov 9, 2008)

AssadUSMC said:


> I haven't used the LWRC piston rifle, but I've used the HK 416 extensively.  I am a HUGE fan of piston over the gas tube.  Look at the FN FAL - probably the 2nd most successful battle rifle ever (after the AK).  Piston design....
> 
> The biggest advantages IMO are 1) maintenance/cleaning and 2) reduced recoil impulse (my subjective impression w/the 416).  I'm currently looking into purchasing an LWRC M6A2 - I need to stop by their shop (about 20 min from me) and have a chat.  If I find out anything new, I'll post it.



Let us know what info you can get from them(LWRC).  Also see if you can demo a weapon! 
Thanks


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## AWP (Nov 9, 2008)

So help me out here. Who makes them? I've found:
Bushmaster, http://www.bushmaster.com/catalog_xm15_BCWA3F16M4-GP.asp
CMMG (though there's no mention of it on their website unless I'm blind):
https://www.budsgunshop.com/catalog/product_info.php/products_id/411535332
LWRC's M6A2: http://www.lwrifles.com/
POF-USA: http://www.pof-usa.com/p415/p415.htm

Any others out there that I missed?


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## AssadUSMC (Nov 9, 2008)

Quietstorm3155 said:


> Let us know what info you can get from them(LWRC).  Also see if you can demo a weapon!
> Thanks



I am going to call them on Monday - it looks like they moved to MD, so it's a little farther away, but if they can help me out, I'll still go visit.  If any of you SSSO guys are in the NOVA area and care to join me, I'll drive.  Just PM me your phone # and I'll give you a call.


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## AssadUSMC (Nov 9, 2008)

Freefalling said:


> So help me out here. Who makes them? I've found:
> Bushmaster, http://www.bushmaster.com/catalog_xm15_BCWA3F16M4-GP.asp
> CMMG (though there's no mention of it on their website unless I'm blind):
> https://www.budsgunshop.com/catalog/product_info.php/products_id/411535332
> ...



Those are the same ones I know, though I'd steer clear of Bushmaster.  Their M4s were breaking left and right on my last deployment.  I stuck to my Colt-mfg.


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## Quietstorm3155 (Nov 9, 2008)

Freefalling said:


> So help me out here. Who makes them? I've found:
> Bushmaster, http://www.bushmaster.com/catalog_xm15_BCWA3F16M4-GP.asp
> CMMG (though there's no mention of it on their website unless I'm blind):
> https://www.budsgunshop.com/catalog/product_info.php/products_id/411535332
> ...



Heres a few more.  There are some good vids on youtube you might want to look at.

Heckler & Koch 416
H&K XM8 
FNH USA's Special Operations Forces Combat Assault Rifle, also known as SCAR Mk16

Check out how the host of future weapons HESITATES big time when the weapons staff gives him the bolt @ 7min mark of the vid.  LMAO, but id react the same way.  He thought hed get blistered :eek:

[ame="http://www.youtube.com/watch?v=gZpZryZEiY4"]YouTube - Future Weapons: Heckler & Koch's HK416 Assault Rifle[/ame]


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## CAL (Nov 9, 2008)

Somebody asked about retrofitting an AR to the gas system.  Here's a company that does it:

http://www.adxtactical.com/store/pc/viewCategories.asp?idCategory=123


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## CAL (Nov 9, 2008)

AssadUSMC said:


> Those are the same ones I know, though I'd steer clear of Bushmaster.  Their M4s were breaking left and right on my last deployment.  I stuck to my Colt-mfg.


Standard (non gas piston) Bushy's were failing?


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## CAL (Nov 9, 2008)

Freefalling said:


> So help me out here. Who makes them? I've found:
> Bushmaster, http://www.bushmaster.com/catalog_xm15_BCWA3F16M4-GP.asp
> CMMG (though there's no mention of it on their website unless I'm blind):
> https://www.budsgunshop.com/catalog/product_info.php/products_id/411535332
> ...


I added Addax tactical to the list here.

Link to Addax Tactical

I'd be curious who makes the piston system for a couple of the folks you listed.  I wonder how many players are in the game.


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## AssadUSMC (Nov 9, 2008)

CAL said:


> Standard (non gas piston) Bushy's were failing?



Yep, broken sears, broken gas keys (!?!?), broken extractors... All kinds of small, piddly crap that could cost you your life.  I had a 416 a while, but the allocation went to a different group of folks.  We may get them again when the next batch arrives.  Low man on the totem pole as I don't kick doors (strictly a defensive thing).


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## CAL (Nov 9, 2008)

AssadUSMC said:


> Yep, broken sears, broken gas keys (!?!?), broken extractors... All kinds of small, piddly crap that could cost you your life.  I had a 416 a while, but the allocation went to a different group of folks.  We may get them again when the next batch arrives.  Low man on the totem pole as I don't kick doors (strictly a defensive thing).


Frankly I'm a bit surprised to hear of Bushys failing.  They have gone through extensive testing without hiccups.  That was several years ago - I wonder if there have been changes made to materials, manufacturing, etc. to cut costs or something that would compromise the reliability.


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## AssadUSMC (Nov 9, 2008)

I bet it has something to do with the big ramp-up in orders.  Some corner somewhere got cut.


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## 08steeda (Nov 9, 2008)

AssadUSMC said:


> Those are the same ones I know, though I'd steer clear of Bushmaster.  Their M4s were breaking left and right on my last deployment.  I stuck to my Colt-mfg.





Yeah I would like more information on this! Is this just an observation or is there some reliable source to validate this statement. I have had BushMasters for a long time now and one was a competition weapon that saw a tremendous amount of use (wear and tear) and I NEVER have had a problem. I mean we are talking thousands of rounds thru the weapon.

I do know that if you buy their higher end rifles they do have different receivers and I always went with a V-Match rig to start with. I never got a M-4 variant from them so I don't know if it has a different receiver or not. I would say my V-Matches are all as reliable as my Colt HBAR.

Can you be more specific or provide a source that confirms this?


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## AssadUSMC (Nov 9, 2008)

08steeda said:


> Yeah I would like more information on this! Is this just an observation or is there some reliable source to validate this statement. I have had BushMasters for a long time now and one was a competition weapon that saw a tremendous amount of use (wear and tear) and I NEVER have had a problem. I mean we are talking thousands of rounds thru the weapon.
> 
> I do know that if you buy their higher end rifles they do have different receivers and I always went with a V-Match rig to start with. I never got a M-4 variant from them so I don't know if it has a different receiver or not. I would say my V-Matches are all as reliable as my Colt HBAR.
> 
> Can you be more specific or provide a source that confirms this?



Yeah, I saw it first-hand both on the range and in Iraq.  Fortunately no one paid the price for it.  My employer is no longer buying Bushmasters as a result - it's all 416s and Colt M4s now.  I don't know how much closer to a source you can get...  We had one break where the rifle would fire both pulling and releasing the trigger.  We had another that would run away full auto (even in semi) when the first round went off.  We had a few that would not cycle after a magazine - problem with the gas key.  Just lots of misc. crap like that.  

Most of you guys know a big part of success in combat is confidence in your gear.  Needless to say, a lot of the guys I know won't come near a Bushmaster anymore.  FWIW, I had a couple Bushmaster civilian guns before, too.  No problems with them - it might just be an M4 thing.


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## Quietstorm3155 (Nov 11, 2008)

I havent got my hands on these gas piston rifles as of yet.  Still doing my .net research.  So far I like what I have seen and read about the LWRC and the HK416.  Heres a couple more vids backing these two up.

[ame="http://www.youtube.com/watch?v=JMZX5WO1uSk"]YouTube - LWRC TESTING[/ame]

[ame="http://www.youtube.com/watch?v=AGwkHktkTxU"]YouTube - HK (Heckler & Koch) versus Colt[/ame]


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## AssadUSMC (Nov 11, 2008)

The 416 is amazing.  I've fired thousands of rounds through both 10" and 14.5" versions (mostly w/EO-Techs).  It's a hammer on full-auto - hardly any climb and a nice cyclic rate.  It's no problem getting 1's and 2's off.  As far as cleaning goes, it's just like an M4 without all the nasty powder residue.  Even when cleaning the piston, it's much neater than the M4.  Think FAL or AK and you'll know what I mean.  I'd trust my life to a 416 any day - it's too bad there's no civilian version (and I can't take the gun home from work).


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## pardus (Nov 11, 2008)

If given a choice I'd always take a gas piston rather than a gas tube.

:2c:


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## AssadUSMC (Nov 11, 2008)

pardus762 said:


> If given a choice I'd always take a gas piston rather than a gas tube.
> 
> :2c:



It's too bad most of our guys in harm's way DON'T have a choice.  That needs to be reconciled ASAP.


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## HOLLiS (Nov 11, 2008)

AssadUSMC said:


> It's too bad most of our guys in harm's way DON'T have a choice.  That needs to be reconciled ASAP.



and?

Charlie had the AK, we had the M16.  More of us came home than him.  Maybe Gunnys today are not what they where back then.


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## pardus (Nov 12, 2008)

HOLLiS said:


> and?
> 
> Charlie had the AK, we had the M16.  More of us came home than him.  Maybe Gunnys today are not what they where back then.



That's unfair.
The servicemen in our current conflict have a great kill ratio, one I wouldn't mind betting is comparable with the kill ratio in Vietnam.


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## HOLLiS (Nov 12, 2008)

pardus762 said:


> That's unfair.
> The servicemen in our current conflict have a great kill ratio, one I wouldn't mind betting is comparable with the kill ratio in Vietnam.




I wonder if Haji would agree with Mr. Charlies on the ineffectiveness of the M4/M16 based rifles.


A small note on the side, I would not be surprised that today's soldiers are more effective.   You just have to be really proud of them.


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## pardus (Nov 12, 2008)

I wonder if there are stats out there with serious malfunctions etc...

I have to think the M series has been tweaked to make it more effective/reliable but that is based on nothing but hope people have done the right thing in the govt :uhh:


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## Quietstorm3155 (Nov 12, 2008)

I must say these are two excellent reviews I have found.  The one talks about the LWRC and the other about the POF P415.  Also for the guys that were asking... the 2nd review covers the "conversion" questions.
  As (AssadUSMC) pointed out earlier, the HK 416 is not availible to purchase privately, so im focusing my research on the POF P415 and LWRC M6.  Anyone with input on these two weapons is greatly appreciated!

http://www.lwrifles.com/content/LWRC.pdf

http://www.pof-usa.com/articles/415OCTGUNDIGEST07.pdf


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## HOLLiS (Nov 12, 2008)

pardus762 said:


> I wonder if there are stats out there with serious malfunctions etc...
> 
> I have to think the M series has been tweaked to make it more effective/reliable but that is based on nothing but hope people have done the right thing in the govt :uhh:



Out side of the new and groovy factor.  I have not really seen anything that says the M4 needs to be canned.


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## pardus (Nov 12, 2008)

Define 'needs'.

I haven't seen the need to replace a rifle since the Garand and SMLE were replaced respectivley with the US/Brit Military.

Just my :2c:


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## HOLLiS (Nov 12, 2008)

pardus762 said:


> Define 'needs'.
> 
> I haven't seen the need to replace a rifle since the Garand and SMLE were replaced respectivley with the US/Brit Military.
> 
> Just my :2c:



I think needs is this situation is that the current battle rifle compared to what is available on the market or what is used by other militaries put our soldiers at a disadvantage.  Some might say that current design changes, such as the gas piston, have sufficient advantages in use and maintenance that would warrant such changes.  I am not sure that is actually a good reason to change to a gp battle rifle for a standard infantry battle rifle.  

Example the change away from the 1911 colt design.  I am a fan of the 1911, but current SA/DA autos have some features that make them more suitable for use as a military side arm (and LE)

The AR platform is a very versatile one.   Also there are difference in needs.  Guys on the teams, know what they need and should get what they want.  A standard battle rifle can be chosen to fit the needs of the average infantry soldier and infantry unit, so far the M4 seem to do the job very well.  Support units have different needs.  

I own both GP and GT ARs.   I can not really say, one is superior to the other, or even a noticeable difference.


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## AssadUSMC (Nov 13, 2008)

Hollis - Here's the problem:  AR types were designed as 20" rifles with gas tubes to match.  When the M4 became mainstream, lots of problems popped up because of the shortened gas tubes.  Too many to detail here, but there are some good articles online with SOCOM and JSOC's issues.  Saved you some research:

http://www.defenseindustrydaily.com/the-usas-m4-carbine-controversy-03289/

The gas piston rifles eliminate those problems.  As for your AK vs. M16 argument, I could argue that if the Joes had AKs, our kill ratio might be even higher.


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## HOLLiS (Nov 13, 2008)

AssadUSMC said:


> Hollis - Here's the problem:  AR types were designed as 20" rifles with gas tubes to match.  When the M4 became mainstream, lots of problems popped up because of the shortened gas tubes.  Too many to detail here, but there are some good articles online with SOCOM and JSOC's issues.  Saved you some research:
> 
> http://www.defenseindustrydaily.com/the-usas-m4-carbine-controversy-03289/
> 
> The gas piston rifles eliminate those problems.  As for your AK vs. M16 argument, I could argue that if the Joes had AKs, our kill ratio might be even higher.



Assad, thank you for the link.    My shorty is a 7 1/2 barrel GT.   I guess for those who are serving, I am far enough out of the loop, so I am harmless.  

My understanding with GT problem, it was poorly designed or manufactured models.  The length and diameter of the GT is important.  Like a weak buffer or wrong buffer can effect performance.  

Again, I'll read the article.  Thank you for post it. 


Several of my friends, other Jar heads, we seem to agree.  One is 27 Year retired Sgt Major (also was a Recon Gunny etc), another a avid shooter a Major.  We shot this stuff pass each other.   I don't think the AK was better.  It is a good CQC battle rifle.    AK Vs AR is one of those ad infinitum discussions.   Probably best over BBQ, Beers and more beers.  I am always available for those discussions.  I have built a number of AKs and ARs.  Personally I value the AR more.


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## HOLLiS (Nov 13, 2008)

Assad, that is a good article.  The advantage mentioned was heat and gasses in the chamber area.  More critical concerns was sand.  

Two statements stood out for me.

"The M4 is the highest-rated weapon by Soldiers in combat, according to the Directorate of Combat Development, Ft. Benning, Ga. In December 2006, the Center for Naval Analysis conducted a “Soldiers’ Perspective on Small Arms in Combat” survey. Their poll of over 2,600 Soldiers reported overwhelming satisfaction with the M4. The survey included serviceability and usefulness in completing assigned missions in Iraq and Afghanistan.”

"“We are not saying the [M4 and M16 are] bad,” said “The issue for me is do our soldiers have the best rifle in their hands…. The fact of the matter is that technology changes every 10 or 15 years and we should be changing with it. And that has not been our case. We have been sitting on this thing for far too long.”


It was also mentioned keeping it clean while one the move.  Well my experience and you can ask any other RVN Bush Marine, that is what was our daily lives.  We did not have a base that we operated out of.   We were mostly always in the bush.  Rain, Mud, Dust, ect.    That point, was meaningless for me.   I don't think my Gunny would accepted either.


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## AssadUSMC (Nov 13, 2008)

FWIW, I primarily use an M4 when I'm overseas.  I take great care of it, shoot on the range regularly, and monitor its performance (weak ejection, bad mags, etc.).  I just know that my M16A2 in the Marines was SUPER reliable - I never once worried about it.  Of course, the 416 is the best 5.56 gun I've ever used.  Problem is, supply is limited so the door-kickers get 'em first.  No argument from me - if I have to fire it, I'm in DEEP caca.


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## HOLLiS (Nov 13, 2008)

AssadUSMC said:


> FWIW, I primarily use an M4 when I'm overseas.  I take great care of it, shoot on the range regularly, and monitor its performance (weak ejection, bad mags, etc.).  I just know that my M16A2 in the Marines was SUPER reliable - I never once worried about it.  Of course, the 416 is the best 5.56 gun I've ever used.  Problem is, supply is limited so the door-kickers get 'em first.  No argument from me - if I have to fire it, I'm in DEEP caca.



I would like to have a 416 too.


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## Quietstorm3155 (Nov 18, 2008)

AssadUSMC said:


> I am going to call them on Monday - it looks like they moved to MD, so it's a little farther away, but if they can help me out, I'll still go visit.  If any of you SSSO guys are in the NOVA area and care to join me, I'll drive.  Just PM me your phone # and I'll give you a call.



Were you able to go check out LWRC?
Anyone here own/shoot a LWRC?


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## AssadUSMC (Nov 18, 2008)

Quietstorm3155 said:


> Were you able to go check out LWRC?
> Anyone here own/shoot a LWRC?



LWRC moved and they've been swamped.  A friend of mine knows the president of LWRC and is trying to "make some arrangements".  If I hear anything, I'll post it.


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## Quietstorm3155 (Nov 20, 2008)

AssadUSMC said:


> LWRC moved and they've been swamped.  A friend of mine knows the president of LWRC and is trying to "make some arrangements".  If I hear anything, I'll post it.


Good to hear.  I am leaning toward that company so I appreciate it.
Out here.


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