Warning

 

Close

Confirm Action

Are you sure you wish to do this?

Confirm Cancel
BCM
User Panel

Page AR-15 » AR Discussions
AR Sponsor: bravocompany
Site Notices
Posted: 12/28/2006 6:04:05 AM EST
did a short reliability test with my AR

here it is:


AR-15 reliability test
Link Posted: 12/28/2006 6:28:41 AM EST
[#1]
Link Posted: 12/28/2006 7:14:46 AM EST
[#2]
wow i could never do that to my ar
Link Posted: 12/28/2006 7:40:05 AM EST
[#3]
Good on the test as i hate the AK and SKS fans who always say the AR sucks because it isnt reliable. BULL CRAP.

As for the "piston weenies" why cant we all just get along? I love both the DI and gas piston, i only own a P.O.F. cause its better in every way




Link Posted: 12/28/2006 7:49:20 AM EST
[#4]

Quoted:
Good on the test as i hate the AK and SKS fans who always say the AR sucks because it isnt reliable. BULL CRAP.

As for the "piston weenies" why cant we all just get along? I love both the DI and gas piston, i only own a P.O.F. cause its better in every way




 No offense meant, it isnt the guys who like pistons who get annoying, but the guys who talk about how unreliable DI is and how pistons are so much better.  On that I call BS.

Link Posted: 12/28/2006 8:07:37 AM EST
[#5]
What does putting sand in the action of an AR15 have to do with a DI vs. Piston comparison?  

Stephen
Link Posted: 12/28/2006 8:55:43 AM EST
[#6]

Quoted:
What does putting sand in the action of an AR15 have to do with a DI vs. Piston comparison?  

Stephen



just demonstrating the reliability of a DI AR-15.  no pistons necessary.
Link Posted: 12/28/2006 10:02:28 AM EST
[#7]

Quoted:

Quoted:
What does putting sand in the action of an AR15 have to do with a DI vs. Piston comparison?  

Stephen



just demonstrating the reliability of a DI AR-15.  no pistons necessary.


Piston driven AR systems aren't designed to reduce/eliminate reduced reliability due to entrance of foreign debris into the action.  Any weapon can choke when dirt and sand are dumped into the operating parts.  Piston systems for the AR15/M4 alleviate the introduction of high heat and carbon fouling into the action which increases the lifespan of the working components and shortens (and nearly eliminates) the time it takes to properly clean the AR.  In addition they greatly improve the reliability of carbines with barrels less than 12 inches.

Stephen
Link Posted: 12/28/2006 10:22:41 AM EST
[#8]

Quoted:
Piston driven AR systems aren't designed to reduce/eliminate reduced reliability due to entrance of foreign debris into the action.  Any weapon can choke when dirt and sand are dumped into the operating parts.  Piston systems for the AR15/M4 alleviate the introduction of high heat and carbon fouling into the action which increases the lifespan of the working components and shortens (and nearly eliminates) the time it takes to properly clean the AR.  In addition they greatly improve the reliability of carbines with barrels less than 12 inches.

Stephen



I am going to have to disagree with you on that.

Heat isnt what kills the bolt in an AR, it is the cyclic stress.  The piston systems put MORE stress on the bolt lugs.

Carbon fouling has never slowed down any ARs I know of, nor is it a big deal as carbon is a natural dry lubricant anyway.

This is a DI gun after 10k rounds, still running fine (not mine):



as for barrels shorter than 12", yes pistons are easier to get proper gas timing, but with the right gas port location and size, DI guns are just as reliable.

Link Posted: 12/28/2006 10:40:19 AM EST
[#9]

Quoted:

Quoted:
Piston driven AR systems aren't designed to reduce/eliminate reduced reliability due to entrance of foreign debris into the action.  Any weapon can choke when dirt and sand are dumped into the operating parts.  Piston systems for the AR15/M4 alleviate the introduction of high heat and carbon fouling into the action which increases the lifespan of the working components and shortens (and nearly eliminates) the time it takes to properly clean the AR.  In addition they greatly improve the reliability of carbines with barrels less than 12 inches.

Stephen



I am going to have to disagree with you on that.

Heat isnt what kills the bolt in an AR, it is the cyclic stress.  The piston systems put MORE stress on the bolt lugs.

Carbon fouling has never slowed down any ARs I know of, nor is it a big deal as carbon is a natural dry lubricant anyway.

This is a DI gun after 10k rounds, still running fine (not mine):

i56.photobucket.com/albums/g177/hjustein/319497.jpg

as for barrels shorter than 12", yes pistons are easier to get proper gas timing, but with the right gas port location and size, DI guns are just as reliable.




I know that rifle is still running and all, but all that carbon buildup makes my scalp itch

I just cant see subjecting any firearm to that kind of abuse, even to make a point.
Link Posted: 12/28/2006 11:08:48 AM EST
[#10]
Do you wipe your ass if you take a dump?  Clean that rifle!  That's an order!
Link Posted: 12/28/2006 12:36:30 PM EST
[#11]
Gas guns with op rods were used in the 1930 so they MUST be better. The direct impingement didn't come about till the 60's and the military has only been using it for 4 decades or so....longer than any other service rifle by a long chalk. If you want a clean running AR, get one of those Kalifornia legal bolt action ones... I bet they run REAL clean. What will they think of next...props on F15s....maybe steam propulsion aircraft carriers.
Link Posted: 12/28/2006 1:19:11 PM EST
[#12]
Nice job...I give you a lot of credit doing that to your AR, not knowing what would happen. Makes me feel a lil more confident in the AR platform when I see one go through that type of test.
Your test reminded me of a video I believe was linked on here showing a guy doing full auto dumps after dropping his AR in dirty water.(Not meant to hijack in anyway)
TO
Link Posted: 12/28/2006 2:34:26 PM EST
[#13]

Quoted:
What will they think of next....maybe steam propulsion aircraft carriers.


Well, hate to disappoint you, but all of our aircraft carriers have been steam powered.  Including the nuclear one I was qualified as a Propulsion Plant Watch Officer on.

Link Posted: 12/28/2006 2:53:06 PM EST
[#14]

Quoted:

Quoted:
What will they think of next....maybe steam propulsion aircraft carriers.


Well, hate to disappoint you, but all of our aircraft carriers have been steam powered.  Including the nuclear one I was qualified as a Propulsion Plant Watch Officer on.



Damn, I forgot Mr. Jose Rossy was doing his technical nazi shit on this forum now. "Oil fired boilers" just didn't slide off the tongue like "steam" did, but I stand corrected.....Clown.
Link Posted: 12/28/2006 3:04:50 PM EST
[#15]

Quoted:

Quoted:

Quoted:
What will they think of next....maybe steam propulsion aircraft carriers.


Well, hate to disappoint you, but all of our aircraft carriers have been steam powered.  Including the nuclear one I was qualified as a Propulsion Plant Watch Officer on.



Damn, I forgot Mr. Jose Rossy was doing his technical nazi shit on this forum now. "Oil fired boilers" just didn't slide off the tongue like "steam" did, but I stand corrected.....Clown.


Well, we've got the Kitty Hawk and that P.O.S. is still floating around
Link Posted: 12/28/2006 4:01:25 PM EST
[#16]
Probably been posted before, but anyway, here's a clip of an AR15 "torture test". Enjoy!!

www.gunsmokeenterprises.net/

Maybe its not scientific, but still quite impressive. I suspect that the one FTF is more due to the Beta mag than the rifle itself.
Link Posted: 12/28/2006 4:49:07 PM EST
[#17]

Quoted:
Probably been posted before, but anyway, here's a clip of an AR15 "torture test". Enjoy!!

www.gunsmokeenterprises.net/

Maybe its not scientific, but still quite impressive. I suspect that the one FTF is more due to the Beta mag than the rifle itself.

Thx RifleDude, that's the one I saw b4..
TO
Link Posted: 12/29/2006 9:40:59 AM EST
[#18]

Quoted:

Quoted:
Piston driven AR systems aren't designed to reduce/eliminate reduced reliability due to entrance of foreign debris into the action.  Any weapon can choke when dirt and sand are dumped into the operating parts.  Piston systems for the AR15/M4 alleviate the introduction of high heat and carbon fouling into the action which increases the lifespan of the working components and shortens (and nearly eliminates) the time it takes to properly clean the AR.  In addition they greatly improve the reliability of carbines with barrels less than 12 inches.

Stephen



I am going to have to disagree with you on that.

Heat isnt what kills the bolt in an AR, it is the cyclic stress.  The piston systems put MORE stress on the bolt lugs.

Carbon fouling has never slowed down any ARs I know of, nor is it a big deal as carbon is a natural dry lubricant anyway.

This is a DI gun after 10k rounds, still running fine (not mine):

i56.photobucket.com/albums/g177/hjustein/319497.jpg

as for barrels shorter than 12", yes pistons are easier to get proper gas timing, but with the right gas port location and size, DI guns are just as reliable.



Cyclic stresses combined with heat is more destructive than the cyclic stresses of a piston gun alone.

Carbon fouling alone will not always cause issue, but carbon fouling combined with inadequate lubrication can and usually does induce malfunctions.  Piston guns are not as dependent on lubrication, nor do they burn off and blow out lubrication as they operate.

I guess we'll have to agree to disagree.  Also, I am refering only to carbine length gas systems.  Rifle length and mid-length DI systems seem to do fine when properly assembled and lubricated.

Stephen
Link Posted: 12/29/2006 9:52:42 AM EST
[#19]
Link Posted: 12/29/2006 10:10:07 AM EST
[#20]

Quoted:
Do you wipe your ass if you take a dump?  Clean that rifle!  That's an order!


LOL!
Link Posted: 12/29/2006 10:24:05 AM EST
[#21]

Quoted:

Quoted:
Piston driven AR systems aren't designed to reduce/eliminate reduced reliability due to entrance of foreign debris into the action.  Any weapon can choke when dirt and sand are dumped into the operating parts.  Piston systems for the AR15/M4 alleviate the introduction of high heat and carbon fouling into the action which increases the lifespan of the working components and shortens (and nearly eliminates) the time it takes to properly clean the AR.  In addition they greatly improve the reliability of carbines with barrels less than 12 inches.

Stephen



I am going to have to disagree with you on that.

Heat isnt what kills the bolt in an AR, it is the cyclic stress.  The piston systems put MORE stress on the bolt lugs.

Carbon fouling has never slowed down any ARs I know of, nor is it a big deal as carbon is a natural dry lubricant anyway.

This is a DI gun after 10k rounds, still running fine (not mine):



as for barrels shorter than 12", yes pistons are easier to get proper gas timing, but with the right gas port location and size, DI guns are just as reliable.


Damn!

And here I thought I was pretty bad ass going to 5000-rounds without cleaning.

No safe queens here.
Link Posted: 12/29/2006 11:23:13 AM EST
[#22]
The temperature the bolt reaches is not hot enough to affect its fatigue strength very much.    You would have to do some seriously extreme full auto shooting to get your bolt over 500 fahrenheit.  At that point your barrel would be glowing and you probably would be either cooking off rounds or no longer have a gas tube.  Think about it this way, if your bolt is hot enough that its fatige strength is being affected, then the round sitting in the chamber is going to be sitting in a barrel that is even hotter than that, which means it is going to cook off.

If you can afford to shoot enough ammo to do that on a regular basis, breaking a bolt lug every now and then is going to be no big deal.

The AR-15s bolt will suffer a fatigue fracture at either the bolt lug or the cam pin hole after enough cycles, even if it never operates above room temperature.  Shooting full auto just means you are going to reach that point quicker since you are going through cycles much faster.  The mechanical stress on the lugs is a far more important factor than the temperature, and the piston system increases those stresses.






Quoted:

Quoted:

Heat isnt what kills the bolt in an AR, it is the cyclic stress.  The piston systems put MORE stress on the bolt lugs.



Depends upon what part of the bolt breaks and under what conditions. Almost all of the bolt breaks I have seen were guns in full-auto, with heat build-up causing metal fatigue.
Link Posted: 12/29/2006 1:19:56 PM EST
[#23]

Quoted:
The direct impingement didn't come about till the 60's and the military has only been using it for 4 decades or so....


direct impingement has been in use since the 1890s on military small arms and was fighting in Indo-China with the French long before we ever showed up....
Link Posted: 12/29/2006 1:37:43 PM EST
[#24]
Link Posted: 12/29/2006 1:47:04 PM EST
[#25]

Quoted:

Quoted:
The temperature the bolt reaches is not hot enough to affect its fatigue strength very much.    You would have to do some seriously extreme full auto shooting to get your bolt over 500 fahrenheit.  At that point your barrel would be glowing and you probably would be either cooking off rounds or no longer have a gas tube.  Think about it this way, if your bolt is hot enough that its fatige strength is being affected, then the round sitting in the chamber is going to be sitting in a barrel that is even hotter than that, which means it is going to cook off.


30 round dump will send it over 500. C-Mag will send it over 1000. Have seen barrels hit 1500+. I have measured it. Have never been able to get a barrel to glow, gas tubes melts around the second C-Mag. Others such as Slugo, have other results. Never had a cookoff. YMMV.




You mean you have measured the temperature of the bolt itself at over 1000 deg F, or just the barrel?  At that temperature the bolt should be glowing a very dull red and losing a good bit of strength.

That is AMAZING!  I have never seen anyone do that before, but if you have and have actually measured it, I definitely stand corrected.

The autoignition temperature of most smokeless powders is from 400 - 800 deg F, so I really dont understand how cookoffs wouldnt occur if your barrel is at 1500 F and the brass is sitting there for any length of time.  I suppose there arent a whole lot of people who would shoot a beta or two and then leave the rifle sitting with a round in the chamber though.

Also, if your barrel is truly at 1500 degrees, it should definitely be glowing cherry red.  Maybe you were in bright sunlight and just didnt notice, but in the dark it should be pretty obvious.


Link Posted: 12/29/2006 1:56:18 PM EST
[#26]
Link Posted: 12/29/2006 2:26:32 PM EST
[#27]

Quoted:
wow i could never do that to my ar
Link Posted: 1/2/2007 7:27:02 AM EST
[#28]

Quoted:

Using an IR thermometer, not with specialized equipment.

Barrel was measured just after the FSB. not at the chamber.

Also, I had a silencer on it which traps a lot more heat.

Yes, in broad sunlight.

Only tested it once, "just to see".

Do a search on 'SLUGO' he has posted good pics of glowing/drooping gas tubes.


Ok, gotchya, the silencer definitley adds a lot of heat retention.  Those numbers are still higher than I would have guessed, even with the can.  Thanks for that info, very very interesting.



Just a little update, I added some pics from when I cleaned my guns this weekend to my original post.

Link Posted: 1/2/2007 7:48:37 AM EST
[#29]
wow

good job brother
Link Posted: 1/2/2007 8:01:52 AM EST
[#30]

Quoted:

Well, we've got the Kitty Hawk and that P.O.S. is still floating around


Not for much longer!!!

I couldn't do that to my rifle either. holy crap
Link Posted: 1/2/2007 1:58:10 PM EST
[#31]
Gunwritr refers to the French using the DI system in Indochina. If he is talking about the MAS-49/56 rifle, "DI" is not the same "DI" as in an AR15. The MAS-49/56 does indeed have a gas tube that runs back into the bolt carrier from up near the front sight. That is where the similarity ends. In the AR15 it blows on down into the carrier and acts upon the bolt. On he MAS-49/56 it simply blows into a hole in the carrier, forcing it rearward. All you have to do is clean out the hole, as it leads to nothing.

I know 'cause I used to have one (chambered in .308 and took FAL mags).  
Link Posted: 1/2/2007 3:18:40 PM EST
[#32]
I love my AR but I also love my mas49/56 in 7.5 & I also have noted their differences. Just like to say hello to a TN person. I was originally from Monteagle, TN ABNAK where are you from?
Link Posted: 1/2/2007 3:51:56 PM EST
[#33]
While few could dispute the DI system in the M16 works, there are better systems.  Take note of the fact that of the latest generation of assault rifles, not one uses the DI gas system.  Why is this?  Simple, there are better ways of doing things.

With that having been said, I don't think that any of the latest generation assault rifles are actually better than the M16, but then, they haven't had 40 years of development yet either.  Give them time, the good ones will rise to the top, and the bad ones will quietly go away. (hopufully)

Whether there are better ways of doing things or not, the M16 still remains a very tough act to follow, and won't be replaced real soon.
Link Posted: 1/2/2007 5:02:01 PM EST
[#34]

Quoted:
I love my AR but I also love my mas49/56 in 7.5 & I also have noted their differences. Just like to say hello to a TN person. I was originally from Monteagle, TN ABNAK where are you from?



Originally from Ohio, but been here almost 11 years. I'm halfway between Nashville and Clarksville.  


I own 2 piston AR's, used to own a third. I also have a DI AR, and have had MANY in the past 20 years or so. Piston guns clean up faster and generally require less maintenance. Those are MY biggest selling points. I still like the DI setup, it's just more of a mess! Of course it's cheaper too.....  
Link Posted: 1/3/2007 2:39:15 PM EST
[#35]
I' m still learning about all the manufacturers of the AR & the many varieties. Most of my experience was with the M16A1 & A2, mossberg 500 & 590 12 ga. & the good ol' 1911 in .45 ACP & .38 Super. Thanks for the reply Abnak.
Page AR-15 » AR Discussions
AR Sponsor: bravocompany
Close Join Our Mail List to Stay Up To Date! Win a FREE Membership!

Sign up for the ARFCOM weekly newsletter and be entered to win a free ARFCOM membership. One new winner* is announced every week!

You will receive an email every Friday morning featuring the latest chatter from the hottest topics, breaking news surrounding legislation, as well as exclusive deals only available to ARFCOM email subscribers.


By signing up you agree to our User Agreement. *Must have a registered ARFCOM account to win.
Top Top