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
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.
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Andy
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
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
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.
DUP…
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 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.
Size.