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9/22/2017 12:11:25 AM
Posted: 9/29/2005 1:36:25 PM EDT
I see this thrown out all the time. Is it so? If it is, then why is RRA and Armalite the only manufacture offering them?
Link Posted: 9/29/2005 3:16:29 PM EDT
No. 16 inch barrels are not more or less reliable than any other barrel length. It is the quality of the gun and how well it is built that determines relative reliability. Charles the Gunsmith.
Link Posted: 9/29/2005 3:34:56 PM EDT
Don't believe everything you hear.
Link Posted: 9/29/2005 3:40:04 PM EDT
A 16" midlength gas system as compared to a 16" carbine gas system is less harsh on internal components. The midlength gas system will cycle slower than a carbine system thus making for a less abusive action. That is what I have been told and if im wrong someone tell me please.
Link Posted: 9/29/2005 3:42:19 PM EDT
This one is going to be fun.



Its VERY informative so far.
Link Posted: 9/29/2005 3:44:34 PM EDT
Link Posted: 9/29/2005 3:46:51 PM EDT

Originally Posted By Lumpy196:
This one is going to be fun.



Its VERY informative so far.




Link Posted: 9/29/2005 4:02:07 PM EDT
Link Posted: 9/29/2005 4:10:27 PM EDT
[Last Edit: 9/29/2005 4:17:31 PM EDT by Not_A_Llama]
I haven't ever seen a quantitative analysis of wear as a function of gas system, but it's irrational to assume that higher port pressures will not lead to some shortening of component lifetimes.

Armalite has their piece on the rifle versus carbine gas systems; though it doesn't show midlengths, I think it's safe to interpolate: www.armalite.com/library/techNotes/tnote48.htm

But wear isn't the crux of the matter. With midlengths, you get a noticeably smoother action, more handguards, and a better sighting plane, in a package that's carbine-length. That alone makes it a worthwhile proposition to me.
Link Posted: 9/29/2005 4:13:45 PM EDT
Link Posted: 9/29/2005 4:16:29 PM EDT
Link Posted: 9/29/2005 4:28:44 PM EDT
[Last Edit: 9/29/2005 4:29:31 PM EDT by gks452]
I don't know about reliablity but the Mid length looks cool. There's too much barrel sticking out of a regular carbine. Plus you get a bit more area to hold onto w/o getting burned. An you can attach the all important bayonet.

Sorry this was not an answer to your question. A well made carbine will work fine and it will take a lot more shooting than the average 3 ARs see to wear one out.
Link Posted: 9/29/2005 4:51:18 PM EDT
Thanks for the info. I've got a spare upper I might just swap for a middy.
Link Posted: 9/29/2005 6:37:15 PM EDT
A 16" midlength gas system as compared to a 16" carbine gas system is less harsh on internal components. The midlength gas system will cycle slower than a carbine system thus making for a less abusive action. That is what I have been told and if im wrong someone tell me please.


I have carbine length gas systems on most of my AR's, and middie on a RRA, and had an Armalite middie I traded off.

The middie length is noticably smoother, feels much more like a 20".
Link Posted: 9/29/2005 6:44:27 PM EDT
I have a RR m4type and a Armalite A4 midlength. Both are great rifles but I do like the looks and feel of longer handguards. I also can feel the difference in recoil. The middy has a little less and cycling is not as jerky or explosive. One does not appear to be any more reliable than the other. If you are looking for something different buy a midlength but I would not sell my carbines.
Link Posted: 9/29/2005 7:12:24 PM EDT
I have no reason not to believe it.

Smoother cycling. The longer gas system lessens the gas pressure, therefore applying less pressure on the bolt, causing less buffer compression which eliminates much of the violent force found in carbines. I would imagine this aids in reliability as the bolt is not coming back as fast or as forceful.

Cleaner running. The longer gas system allows for more of the gas to burn up before contacting the bolt. I'm not sure how true that is, but a well documented test would be very interesting.

Parts wear. I couldn't see how the lower gas pressures wouldn't have an affect on wear. The slowing in bolt speed has to be a significant amount better on friction. The smoother cycling seems like it would also be more stable as it's not as violent of an action also.

Sight radius. IIRC, mid length gas systems are about 2 inches longer than a standard carbine. I'd imagine this is pretty self explanitory.

Added handguard length. Obviously, less chance to be burned and more area to hold on to.

I myself like the concept of the mid length gas system. Some of the problems can be fixed by heavier carriers and buffers and such, but the added sight radius is a plus, as is the extra handguard space. I don't think I'll have a carbine gas system anytime soon.


Link Posted: 9/29/2005 7:15:25 PM EDT
Link Posted: 9/29/2005 7:19:32 PM EDT
Over the long term, the midlength would seem to be more reliable, but out of the box, both are proven.
Link Posted: 9/29/2005 7:22:04 PM EDT
Both are very proven, and even in the event that one (carbine) was to have cyclic issues, it can be easily fixed. I like them more because I think they look cool.
Link Posted: 9/29/2005 7:24:27 PM EDT
RRA and Armalite are not the only manufactures of mid lengths. Sabre has one, Cavalry uses Sabre for theirs (I think) There's also dealers around here that are getting them from other manufactures. Do a search for midlength and you'll see who all is making them.

More reliable? Some seem to think so due to the slower cycling, it gives the bolt more time to do what it needs to do. I guess thats why people use H buffers in their carbines---to slow things down a bit. Although I've never had a problem with a standard buffer in my carbine.
My midlength is definitely sweet and have yet to have any malfunction in about 700-800 rounds.
FWIW: my middy is a Sabre Defence.

1911builder: this is about gas systems, not barrel length
Link Posted: 9/29/2005 8:03:17 PM EDT
[Last Edit: 9/29/2005 8:08:52 PM EDT by HankC]
I can see the theoretical advantage of a midlength, but I guess I should also put enough confidence on a 16" carbin in civilian usage if our soliders can trust their 14.5" and 11.5" carbins with their lives. What bothers me is if midlength is really that much better, we should have seen more manufacturers jumped into it specially in 16" applications.
Link Posted: 9/29/2005 9:00:20 PM EDT
[Last Edit: 9/29/2005 9:00:48 PM EDT by WIZZO_ARAKM14]

Originally Posted By HankC:
I can see the theoretical advantage of a midlength, but I guess I should also put enough confidence on a 16" carbin in civilian usage if our soliders can trust their 14.5" and 11.5" carbins with their lives. What bothers me is if midlength is really that much better, we should have seen more manufacturers jumped into it specially in 16" applications.







As HeavyMetal said above, they are a relatively new (especially so compared to the rifle and traditional carbine gas systems). More manufacturers are getting on-board. Once again, as stated above, Sabre Defence has one (and I have one of their barrels). It is only a matter of time before more of the big-name guys start making them. A large number of aftermarket companies have started making rails and other acessories for the middies. They aren't going away anytime soon, IMO.

WIZZO
Link Posted: 9/29/2005 9:18:39 PM EDT
Would the RRA 18" Wilson barrel pictured below be considered a Mid-length gas system? Compared to the 16" pictured, the distance from the chamber to the gas block is longer for the 18", but not as long as the 20".


Link Posted: 9/29/2005 9:28:40 PM EDT

Originally Posted By olds442tyguy:
Cleaner running. The longer gas system allows for more of the gas to burn up before contacting the bolt. I'm not sure how true that is, but a well documented test would be very interesting.



How in the world does the gas burn up?

With a longer gas tube (more resistance) the gas velocity is reduced resulting in a smoother cycling rifle - not quite a 20" but darn close...
Link Posted: 9/30/2005 2:42:51 AM EDT

Originally Posted By darealickt:
Would the RRA 18" Wilson barrel pictured below be considered a Mid-length gas system? Compared to the 16" pictured, the distance from the chamber to the gas block is longer for the 18", but not as long as the 20".

www.rockriverarms.com/images/bblv.gif



The 18" appears to be midlength.
Link Posted: 9/30/2005 3:16:27 PM EDT

Originally Posted By BerlinVet:

Originally Posted By olds442tyguy:
Cleaner running. The longer gas system allows for more of the gas to burn up before contacting the bolt. I'm not sure how true that is, but a well documented test would be very interesting.



How in the world does the gas burn up?

With a longer gas tube (more resistance) the gas velocity is reduced resulting in a smoother cycling rifle - not quite a 20" but darn close...


I should have worded that differently. There's multiple elements released from a fired rounds propellant. In theory, the longer it takes these elements to reach the gas port, the more time they have to be sufficiently "processed". Picture muzzle blast on a short barrel as opposed to a longer one.
Link Posted: 9/30/2005 3:35:25 PM EDT
are you asking how does gas burn up or are you trying to say it doesn't burn up? I'm thinking he means completely combust. You want the combustion to finish as quickly as possible for the shortest flash and that's what the Vortex is best at and likewise having an extra few inches of room to combust before the burning gases enter the gas key and carrier is nice as well...
Link Posted: 9/30/2005 3:43:53 PM EDT

Originally Posted By JosephR:
having an extra few inches of room to combust before the burning gases enter the gas key and carrier is nice as well...



Exactly, and the mid length adds about 4 inches of overall length to the path in which the gas must travel to contact the key. The added length gives all of the propellants more time to do their job before reaching the bolt assembly.
Link Posted: 9/30/2005 3:54:17 PM EDT
Link Posted: 9/30/2005 4:57:50 PM EDT
Has anyone tried the PRI fatboy?

I wonder if this would replace some of the negatives of the carbine with the positives of the mid-length?
Link Posted: 9/30/2005 5:00:32 PM EDT
Link Posted: 10/1/2005 7:18:09 AM EDT
Thanks Metal,

I think I'll try and pick one up at Knob Creek in a couple of weeks.
Link Posted: 10/1/2005 8:54:22 AM EDT
Haven't we beat his one to death a dozen times before...

Theoretically, as mentioned, it is easier on the bolt and carrier due to lower peak pressure. But then again, theoretically a bumblebee can't fly.
Link Posted: 10/1/2005 9:05:52 AM EDT
Link Posted: 10/1/2005 9:17:58 AM EDT
Can anyone really honestly say that they have had enough of a reliability issue with a carbine to switch to midlength? Or is it just that we want something different?
Link Posted: 10/1/2005 9:19:31 AM EDT

Originally Posted By C4iGrant:
The mid-length gas system is the way to go. I will NEVER own another carbine gas system again (less a 10.5). Recoil, wear/tear on the weapon and the mid-length gas system is the most reliable as it operates in extreme temperature conditions the best.

C4



Must be why the military is switching over to the mid length right?

Becasuse they perform so much better in extreme conditions.....................
Link Posted: 10/1/2005 9:34:48 AM EDT
Link Posted: 10/1/2005 9:35:30 AM EDT

Originally Posted By HeavyMetal:

Actually they have improved their model and there is no longer a conflict between bumblebee flight and modern aerodynamic theory.



I guess that would be the new Mark xx Mod 1 bumblebee , right?
Link Posted: 10/1/2005 9:43:21 AM EDT
Link Posted: 10/1/2005 9:52:08 AM EDT
Yep, this thread's over when we get the "Then I suppose that's why the military is throwing away XXX and replacing it with YYY" comments. Yeah, that wouldn't happen in the real world even if a super gun were developed.
Link Posted: 10/1/2005 9:54:14 AM EDT
Link Posted: 10/2/2005 3:23:05 PM EDT

Originally Posted By Dace:

Originally Posted By C4iGrant:
The mid-length gas system is the way to go. I will NEVER own another carbine gas system again (less a 10.5). Recoil, wear/tear on the weapon and the mid-length gas system is the most reliable as it operates in extreme temperature conditions the best.

C4



Must be why the military is switching over to the mid length right?

Becasuse they perform so much better in extreme conditions.....................



Link Posted: 10/4/2005 6:33:49 PM EDT
I think the midlength is the best if you are not going to SBR the rifle.

If you are going SBR, then don't matter much.. that or just going with what God Stoner intended and get the 20"

And as mentioned.. you have a bayonet.
Link Posted: 10/4/2005 7:02:35 PM EDT
Link Posted: 10/4/2005 7:14:27 PM EDT

Originally Posted By C4iGrant:
The military NEVER gets the best gear and cannot just go out and buy whatever they want for duty use. When I built my Noveske 18" SPR barrels, I received input directly from an Army SF unit that experienced issues with rifle length gas systems and cold weather. They knew that a mid-length gas system was a better choice. Could they do anything about it? No.

C4




In cold weather does the tollerance of the bolt to chamber become to small? Does the gas cool too much to do a proper cycle? (Naa....)
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