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7/8/2020 3:01:36 PM
Posted: 8/31/2015 1:56:57 PM EDT
Not asking for a 6920 vs HK416 comparison , but between the 6920 and something like a huldra, adams arms or SR556.

I realize that going from DI to piston will cause a technical drop in SOME accuracy simply due to the piston's movement, however in the case of the SR556 the barrel is supposedly free floated, which may be a trade-off that negates the effect of the piston, but that's a whole other story.

I'm mostly looking for the end reliability the average user might see between the 6920 (Or another higher-end rifle like a DD) and one of the many easily purchasable piston rifles.

The Rugers initially had some carrier tilt issues, but those seem to have been resolved quite some time ago with most users reporting fantastic reliability out of them. In my case though I have not once experienced a jam in any of my AR15s, whether it be a 6920 or a bargain basement one. n one of my more recent AK accuracy threads, the general consensus was that you traded reliability for accuracy, however with a piston it seems to put the reliability in a very good place while retaining almost all of the AR's fantastic battle rifle accuracy.
Link Posted: 8/31/2015 1:58:16 PM EDT
Putting a piston in your AR doesn't increase the reliability.



Spend your money how you want to.


Link Posted: 8/31/2015 2:00:23 PM EDT
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By peekay:
Putting a piston in your AR doesn't increase the reliability.

Spend your money how you want to.
View Quote

agreed.
Link Posted: 8/31/2015 2:03:57 PM EDT
I have high end piston and DI guns. I can't tell the difference in accuracy or reliability. Piston guns are much cleaner and easier to clean.

Link Posted: 8/31/2015 2:14:48 PM EDT
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Originally Posted By Canoeguy:

agreed.
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Originally Posted By Canoeguy:
Originally Posted By peekay:
Putting a piston in your AR doesn't increase the reliability.

Spend your money how you want to.

agreed.


From what I had read, I was under the impression that the M4 (Which i understand to be a 6920 with 14.5" barrel and happy switch) has a MTBF well under what a piston rifle runs.
Link Posted: 8/31/2015 2:19:56 PM EDT
Your AR already has a piston.



Check out the stickies in the Adco forum.



More relevant to your discussion, I have been wanting to check out a Colt 6940P.
Link Posted: 8/31/2015 2:23:09 PM EDT
Unless running suppressed, I myself don't see the benefit to pistons.
Aside from the 'clean' part
And, DI does just fine suppressed, just dirtier

I'd rather spend the additional $ on ammo, optics, etc



Then again, nothing goes back into my safe without getting cleaned first
You may not be as OCD as I, in which case pistons may not be a bad thing
Link Posted: 8/31/2015 2:23:23 PM EDT
For the Crimson Trace midnight 3 gun, PWS supplied full auto SBR's as stage guns. Those guns ran 60 rounds per shooter, 10 shooters per squad, approximately 5 squads per night. I believe they rotated 2 or maybe 3 guns to manage overheating, but the reliability made an impression on me.
Link Posted: 8/31/2015 2:24:03 PM EDT
[Last Edit: 8/31/2015 2:29:12 PM EDT by avslash]


Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Shockergd:
From what I had read, I was under the impression that the M4 (Which i understand to be a 6920 with 14.5" barrel and happy switch) has a MTBF well under what a piston rifle runs.
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Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Shockergd:





Originally Posted By Canoeguy:




Originally Posted By peekay:


Putting a piston in your AR doesn't increase the reliability.





Spend your money how you want to.





agreed.








From what I had read, I was under the impression that the M4 (Which i understand to be a 6920 with 14.5" barrel and happy switch) has a MTBF well under what a piston rifle runs.
The DI gun actually fared pretty well in the "fall retest" of the extreme dust test.  If you exclude magazine related failures, I believe it had less stoppages than the SCAR 16 or the 416.





Going from memory, but I'm sure the results are still on the archive server somewhere.



ETA:  had my timing wrong.  The fall test was the one with the large disparity (allegedly due to the burst function on the m4).









 
Link Posted: 8/31/2015 2:27:06 PM EDT
It pretty much boils down to a cleaning issue.  How much do you want to spend to only have to run a snake down your bore and maybe wipe down your bolt carrier group every blue moon?   To me, I haven't had the money to throw away since I got married
Link Posted: 8/31/2015 2:30:10 PM EDT
I personally don't get to shoot enough to tell you about DI vs Piston reliability.  I bought one (LWRC SPR) because I wanted it and the gunstore was going out of business.

Having shot several iterations of the piston AR, I can tell you the recoil impulse is different than a DI rifle.  Accuracy inside of 150 yds was no different than the DI guns. The piston guns are dramatically cleaner than the DI rifles.


Even back in the days of 1k round range sessions, I never had many issues with my DI rifles.  I've put maybe a couple thousand rounds through the LWRC now and I've had no issues to report.


If you want a piston rifle, get one.  Just don't expect miraculous improvements.
Link Posted: 8/31/2015 2:31:47 PM EDT
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By dogbert4-1:
It pretty much boils down to a cleaning issue.  How much do you want to spend to only have to run a snake down your bore and maybe wipe down your bolt carrier group every blue moon?   To me, I haven't had the money to throw away since I got married
View Quote



The price of piston guns keeps coming down unless you're talking a MR556 or such. The SR556s are on sale for around $900 which is right in the range of a 6920 unless you found one with the big walmart deal recently. I love both of my 6920s, however if there's something better I could get for similar money, i'd be ok with selling off one of my cheap builds and replacing it with a nicer rifle.
Link Posted: 8/31/2015 2:45:20 PM EDT
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By buckshot_jim:
I have high end piston and DI guns. I can't tell the difference in accuracy or reliability. Piston guns are much cleaner and easier to clean.

View Quote


Pretty much this. I sold all my DI's and have all piston now. With the exception of my .50 Beowulf, but I'm working on a solution to piston that as well.
Link Posted: 8/31/2015 2:46:32 PM EDT


I had an SR556. It looked neat, but didn't really do anything special that any other AR won't do.

It got sold or traded.

Link Posted: 8/31/2015 2:49:32 PM EDT
Didn't that guy from Battlefield Vegas say that the piston ARs (aside from the 416) were less reliable? Not surprising. The Marines and various other countries seem to like their HKs...

IMO I'd just get a cheap 6920. Most of the small name piston ARs were never subjected to abuse and who knows how the part situation will be 3-5 years down the road.
Link Posted: 8/31/2015 4:12:40 PM EDT
I see no reason to fix something thats not broke.
Link Posted: 9/1/2015 9:15:22 PM EDT
After reviewing all the opinions I think i'll go for a third 6920 unless anyone can offer a better deal for me to think about. Took my socom out with the 4-12x Nikon scope I have for it and was very, very pleased with the performance.

How many is too many?
Link Posted: 9/1/2015 9:25:57 PM EDT
[Last Edit: 9/1/2015 9:26:46 PM EDT by squashpup]
I've never had a failure with any of my AR's due to the lack of a piston. Crap mags, crap ammo, yes, but never anything else.

As for cleaning, disassembling the BCG and soaking for a bit in foaming bore scrubber while you're doing the barrel/chamber is no big deal and does a reasonably good job with little effort..
Link Posted: 9/1/2015 9:31:29 PM EDT
Meh.  Get the Colt.  Spend the difference on ammo.
Link Posted: 9/1/2015 9:31:32 PM EDT
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Canoeguy:

agreed.
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Originally Posted By Canoeguy:
Originally Posted By peekay:
Putting a piston in your AR doesn't increase the reliability.

Spend your money how you want to.

agreed.


X2
Hardware fix for a software problem
Link Posted: 9/1/2015 9:34:11 PM EDT

Discussion ForumsJump to Quoted PostQuote History
Originally Posted By avslash:



The DI gun actually fared pretty well in the "fall retest" of the extreme dust test.  If you exclude magazine related failures, I believe it had less stoppages than the SCAR 16 or the 416.



Going from memory, but I'm sure the results are still on the archive server somewhere.



ETA:  had my timing wrong.  The fall test was the one with the large disparity (allegedly due to the burst function on the m4).



http://1.bp.blogspot.com/_9z0kZs2YpZg/R3seWbcGmKI/AAAAAAAAAKI/l8qvBq6S-eE/s400/EDT-6.jpg

 
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Discussion ForumsJump to Quoted PostQuote History
Originally Posted By avslash:



Originally Posted By Shockergd:


Originally Posted By Canoeguy:


Originally Posted By peekay:

Putting a piston in your AR doesn't increase the reliability.



Spend your money how you want to.



agreed.





From what I had read, I was under the impression that the M4 (Which i understand to be a 6920 with 14.5" barrel and happy switch) has a MTBF well under what a piston rifle runs.
The DI gun actually fared pretty well in the "fall retest" of the extreme dust test.  If you exclude magazine related failures, I believe it had less stoppages than the SCAR 16 or the 416.



Going from memory, but I'm sure the results are still on the archive server somewhere.



ETA:  had my timing wrong.  The fall test was the one with the large disparity (allegedly due to the burst function on the m4).



http://1.bp.blogspot.com/_9z0kZs2YpZg/R3seWbcGmKI/AAAAAAAAAKI/l8qvBq6S-eE/s400/EDT-6.jpg

 
This is a situation where people will ignore blatant facts and insist DI is as or more reliable than a piston.  Then make up random "facts" about how the test is biased.

 



Even more sad, these people are the same that bash moronic libtards for doing the exact same thing.  
Link Posted: 9/1/2015 9:38:20 PM EDT
Link Posted: 9/1/2015 9:56:47 PM EDT
Discussion ForumsJump to Quoted PostQuote History
And yet you predicted the XM-8 would replace the M-4 ten years ago.

You are a fine one to be lecturing people about accuracy sparky.
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Isn't the XM8 more or less the G36 with a little Americanization done to it?
Link Posted: 9/1/2015 10:05:27 PM EDT
Link Posted: 9/1/2015 10:06:50 PM EDT
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By buckshot_jim:
I have high end piston and DI guns. I can't tell the difference in accuracy or reliability. Piston guns are much cleaner and easier to clean.

View Quote



I know how you texans hate getting your nails dirty

Just get a DI I'd say its more reliable and lighter.
Link Posted: 9/1/2015 10:08:05 PM EDT
[Last Edit: 9/1/2015 10:09:59 PM EDT by Evil_Ryu]
I have an Adams Arms piston carbine. Got a blem model from Buds that looked perfect to me.  Slapped on some Magpul furniture and a Geissle trigger.

Its nice running Wolf through it and not worrying about cartridges getting stuck nor inhaling its nasty funk.  Accuracy with brass was on par with my Rock River DI.  I'm all in for pistons.
Link Posted: 9/1/2015 10:13:48 PM EDT

Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Evil_Ryu:


I have an Adams Arms piston carbine. Got a blem model from Buds that looked perfect to me.  Slapped on some Magpul furniture and a Geissle trigger.



Its nice running Wolf through it and not worrying about cartridges getting stuck nor inhaling its nasty funk.  Accuracy with brass was on par with my Rock River DI.  I'm all in for pistons.
View Quote




 
I have 2 AA's in 5.45, 2 Ruger SR556's and various caliber DI guns.




They all have their merits, but I prefer the piston guns.
Link Posted: 9/1/2015 10:14:15 PM EDT
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By avslash:
Your AR already has a piston.

Check out the stickies in the Adco forum.

More relevant to your discussion, I have been wanting to check out a Colt 6940P.
View Quote


Thank you.
Link Posted: 9/1/2015 10:14:59 PM EDT
How does the Colt piston gun compare to the other piston models on the market?

Link Posted: 9/1/2015 10:15:09 PM EDT
[Last Edit: 9/1/2015 10:17:48 PM EDT by lazyengineer]
Go read the Las Vegas machine gun rental thread, on high round count AR's.  The piston ARs break (usually bent rods).  The DI's didn't, they keep chugging.  

Piston AR's are a wildly successful marketing scheme.
http://www.ar15.com/forums/t_3_118/677135_High_round_count_AR_M4_s__over_100_000_rounds__and_how_they_have_handled_on_our_range.html


Link Posted: 9/1/2015 11:09:48 PM EDT
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By lazyengineer:
Go read the Las Vegas machine gun rental thread, on high round count AR's.  The piston ARs break (usually bent rods).  The DI's didn't, they keep chugging.  

Piston AR's are a wildly successful marketing scheme.
http://www.ar15.com/forums/t_3_118/677135_High_round_count_AR_M4_s__over_100_000_rounds__and_how_they_have_handled_on_our_range.html


View Quote


Wow.

I need some DD BCGs and a set of gas tubes :D
Link Posted: 9/1/2015 11:26:22 PM EDT

Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Rem700PSS:



This is a situation where people will ignore blatant facts and insist DI is as or more reliable than a piston.  Then make up random "facts" about how the test is biased.  



Even more sad, these people are the same that bash moronic libtards for doing the exact same thing.  

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Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Rem700PSS:



Originally Posted By avslash:


Originally Posted By Shockergd:


Originally Posted By Canoeguy:


Originally Posted By peekay:

Putting a piston in your AR doesn't increase the reliability.



Spend your money how you want to.



agreed.





From what I had read, I was under the impression that the M4 (Which i understand to be a 6920 with 14.5" barrel and happy switch) has a MTBF well under what a piston rifle runs.
The DI gun actually fared pretty well in the "fall retest" of the extreme dust test.  If you exclude magazine related failures, I believe it had less stoppages than the SCAR 16 or the 416.



Going from memory, but I'm sure the results are still on the archive server somewhere.



ETA:  had my timing wrong.  The fall test was the one with the large disparity (allegedly due to the burst function on the m4).



http://1.bp.blogspot.com/_9z0kZs2YpZg/R3seWbcGmKI/AAAAAAAAAKI/l8qvBq6S-eE/s400/EDT-6.jpg

 
This is a situation where people will ignore blatant facts and insist DI is as or more reliable than a piston.  Then make up random "facts" about how the test is biased.  



Even more sad, these people are the same that bash moronic libtards for doing the exact same thing.  


You will notice that I used "allegedly" as the reason for testing discrepancy.  I have heard that reason as internet rumor, but I have never seen a verifiable reference to back that up.


Unless you disagree that the posted slide is from the report in question, my original statement stands.  In one of the tests conducted, excluding magazine failures, the m4 had fewer stoppages than the SCAR16 or HK416.








 
Link Posted: 9/1/2015 11:34:01 PM EDT

Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Bunn19:


How does the Colt piston gun compare to the other piston models on the market?



View Quote

I'm kicking myself for not picking one up when a retailer had them for $1,200ish.  I've never seen them that low again.


Their marketing schtick touts that their piston has an articulating link in the op rod, which supposedly mitigates some issues inherent in piston AR's.  I can't comment on how well it works.  One item I have heard some complain about is that the 6940P uses Colt's monolithic upper, so you are locked in to the carbine length quad rail on that item.  Not an issue for me, but some seem to not like it.


I would also be curious to hear anyone chime in that has a high round count Sig 516, and if they have had any issues, or not.





 
Link Posted: 9/2/2015 12:25:38 AM EDT
[Last Edit: 9/2/2015 12:26:07 AM EDT by Krink]
all my AR's have been DI since I built my first one in 85,dont see any reason to change now..

I would get the 6920

Link Posted: 9/2/2015 12:45:31 AM EDT
Reliablity/accuracy aside (and I think that is probably splitting hairs), the advantage of the piston, to me, is the ability to have a folding stock.

If you need to fit a firearm in a small case/area, this can be a real advantage.
Link Posted: 9/2/2015 12:55:52 AM EDT
The only difference I notice between my DI and piston ARs are that the Piston AR kicks a bit more, so nose to charging handle is a bad idea AND the piston AR doesn't blow any gas back in my face when shooting suppressed.  Other than that, I've seen no significant reliability increases or reduced accuracy issues with my POF rifle compared to my DI rifles.  Of course, YMMV!
Link Posted: 9/2/2015 9:00:39 AM EDT
[Last Edit: 9/7/2015 2:34:11 PM EDT by LARRYG]
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Rem700PSS:
This is a situation where people will ignore blatant facts and insist DI is as or more reliable than a piston.  Then make up random "facts" about how the test is biased.  

Even more sad, these people are the same that bash moronic libtards for doing the exact same thing.  
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Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Rem700PSS:
Originally Posted By avslash:
Originally Posted By Shockergd:
Originally Posted By Canoeguy:
Originally Posted By peekay:
Putting a piston in your AR doesn't increase the reliability.

Spend your money how you want to.

agreed.


From what I had read, I was under the impression that the M4 (Which i understand to be a 6920 with 14.5" barrel and happy switch) has a MTBF well under what a piston rifle runs.
The DI gun actually fared pretty well in the "fall retest" of the extreme dust test.  If you exclude magazine related failures, I believe it had less stoppages than the SCAR 16 or the 416.

Going from memory, but I'm sure the results are still on the archive server somewhere.

ETA:  had my timing wrong.  The fall test was the one with the large disparity (allegedly due to the burst function on the m4).

http://1.bp.blogspot.com/_9z0kZs2YpZg/R3seWbcGmKI/AAAAAAAAAKI/l8qvBq6S-eE/s400/EDT-6.jpg
 
This is a situation where people will ignore blatant facts and insist DI is as or more reliable than a piston.  Then make up random "facts" about how the test is biased.  

Even more sad, these people are the same that bash moronic libtards for doing the exact same thing.  


How about the FACT that the M4/M16/AR15/etc are indeed piston guns, internal pistons, and are not DI guns.

And where are these "blatant facts" you speak of?  The only times I see these supposed "facts" is when someone is trying to sell DOD a new gun,
Link Posted: 9/2/2015 9:19:43 AM EDT
What the fuck is it with people's obsession with piston guns.
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