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prepare
07-24-21, 07:55
Why was the carbine buffer system developed/engineered when the rifle buffer system works well across the spectrum as the VLTOR A5 system has proved?

The VLTOR A5/rifle RE is only 3/4" longer than a carbine RE so being more compact is kind of insignificant.

AndyLate
07-24-21, 10:14
Why was the carbine buffer system developed/engineered when the rifle buffer system works well across the spectrum as the VLTOR A5 system has proved?

The VLTOR A5/rifle RE is only 3/4" longer than a carbine RE so being more compact is kind of insignificant.

No offense, but are you seriously asking that question? See Tom 12.7's answer on page 2. https://www.m4carbine.net/showthread.php?173654-Why-Is-The-Carbine-Buffer-Only-3-oz

Andy

utahjeepr
07-24-21, 10:16
Development of the carbine with the collapsible stock started the carbine buffer train rolling. Colt spent a lot of time, effort, money tweaking the design before it hit the wild. Everybody else just ran with it.

That said, the VLTOR A5 ain't simply the rifle system. The rifle buffer has about 2 inches of spacer built into it. The spacer is to allow the rifle buffer tube to match the designed stock length. VLTOR didn't start down the A5 path looking to improve the carbine system. They were looking to shorten USMC rifle stocks to better suit modern armor use. The eventual end product was the A5 collapsible stock system.

Colt designers started with a blank page and built the carbine system from scratch. VLTOR was intending to modify the rifle system. That they created a hybrid that works so well is 1 part accident 9 parts ingenuity.

Looking at it now it seems obvious, but often the so called "obvious" solutions are the hardest to see. Hindsight blah, blah.

AndyLate
07-24-21, 10:25
Deleted

Andy

prepare
07-24-21, 11:34
No offense, but are you seriously asking that question? See Tom 12.7's answer on page 2. https://www.m4carbine.net/showthread.php?173654-Why-Is-The-Carbine-Buffer-Only-3-oz

Andy


About, 25 years ago, I asked some of the decision makers about this, the same thing. They knew that the carbine uppers could run with a wider span with a rifle action system on the lower compared to the carbine type system on the lower. It wasn't a secret then more than it is now. The rifle like action system worked better overall in function. It is a function of timing of events.
When asked specifically about the spring, RE length selection, and buffer mass, some interesting things came up.
The buffer mass was pushed as the most viable option at that time. I get conflicting reports of suitable tungsten weight inserts during those times being available for small or large production. Anyways, steel was accepted at the time knowing that is has the lower span of function when compared to a heavier one that may not have the ability to supply as components.
The RE length was meant to fit an AOL requirement that some wanted. I do not know where that came from, but it was a requirement at some time. On the base gun, the rifles ran worse for the requirement with less barrel length than less RE length. It was an consensus that to have more barrel length and less RE length. I do not know if this happened before or after the choice of tungsten weights was eliminated?
As for the spring? It was a modified rifle spring intended to work within the shorter RE dimensions. That functioned well enough, but less than ideal.
This was all done knowing that the rifle like action system performed better. They ended with a functional system, but with the addition of issues. I really think that the 3 ounce carbine action is a mistake for most. Even with proper porting, a 3 ounce buffer may have a lower range or span on function when considering the alternatives we have now.
Some AR's have longer gas systems to help address some base timing of events issues. A better way may or may not include that with a rifle like action system. The idea of the commercial A5, minus the internal spring, has been around since before my inital question a quarter century ago. Many different versions have been around in at least limited circulation from before my time.
I can not see in any way that the properly gassed 3 ounce carbine buffer action system can have any more of a range in function than a properly gassed version of the A5H2 system.

Toms inquiries didn't reveal any definitive conclusions

AndyLate
07-24-21, 12:16
Toms inquiries didn't reveal any definitive conclusions

Its unlikely you will find definitive conclusions backed with verifiable documentation by asking a question on the internet.

The first carbine REs were two position - fully collapsed, meeting an OAL target, and fully extended, equal to an M-16 LOP.

A longer RE would not meet the OAL target without a shorter barrel. A shorter RE would not allow an M-16 LOP.

Andy

prepare
07-24-21, 13:43
Its unlikely you will find definitive conclusions backed with verifiable documentation by asking a question on the internet.

The first carbine REs were two position - fully collapsed, meeting an OAL target, and fully extended, equal to an M-16 LOP.

A longer RE would not meet the OAL target without a shorter barrel. A shorter RE would not allow an M-16 LOP.

Andy

Thanks for the info and the link to Tom12.7

He doesn't appear to be around anymore?

AndyLate
07-24-21, 14:22
Thanks for the info and the link to Tom12.7

He doesn't appear to be around anymore?

I have not seen him post for a while, no activity since 2018.

Andy

GH41
07-24-21, 19:38
I'll stick my neck out... Why would you change gas from or to carbine, mid or rifle if your rifle works as it is? Maybe I am not smart enough to see the benefit of one over the others.

prepare
07-24-21, 19:51
I'll stick my neck out... Why would you change gas from or to carbine, mid or rifle if your rifle works as it is? Maybe I am not smart enough to see the benefit of one over the others.

The question I was asking is why didn't the engineers stick with the rifle length buffer system? Nobody mentioned gas system.

Clint
07-25-21, 13:32
DUP.....

Clint
07-25-21, 13:33
The bottom line is they were tasked with designing a much more compact version of the weapon, which included shortening both the barrel and stock.

This was the Colt 607/610/XM-177.

Compromises were made to meet an overall length target requirement.


We now know that they were probably a bit too aggressive with the 10" barrel and 7" RE.

Much better reliability is obtained with an 11.5" barrel and 7.75" RE containing a 4 weight buffer and rifle spring.

Hind sight is 20/20 and all...


The question I was asking is why didn't the engineers stick with the rifle length buffer system? Nobody mentioned gas system.

lysander
07-30-21, 14:07
The question I was asking is why didn't the engineers stick with the rifle length buffer system? Nobody mentioned gas system.
The requirement was for a submachine gun with an overall length of 26 inches, or less, in compact condition. Most applicant weapons used a folding stock, but folding the receiver extension was considered too complicated and would allow dirt in the system unless you got really complicated.

This requires both ends to be cut down.

(Originally, the Army specified an 16 inch barrel as well as the 26 inch folded length, but dropped that requirement when it became quite obvious the AR design would not allow for that in any practical manner.)

The M4 was specified to use as many already developed concepts as possible, and the carbine buffer system and the carbine gas system were already developed and working reasonably well in the XM177E2, they did not have the resources available to change them.

markm
07-30-21, 14:46
Why was the carbine buffer system developed/engineered when the rifle buffer system works well across the spectrum as the VLTOR A5 system has proved?


Size.