Looking at images at various resellers, it appears that the buffer and spring are shorter. Will it work on a non-carbine rifle? I guess part of the confusion is what constitutes a carbine? Is it the 16 inch barrel and carbine length gas tube? If I have an 18 inch barrel and a mid-length gas tube, will a carbine stock work? Some explanation to further my understanding would sure be great.
Think of the upper group and the lower group as two separate things.
You can have a rifle length gas system and 18 or 20 inch barrel upper and put it on a lower with a carbine stock.
Or you can have a carbine length gas system wit a 16 or 14.5 or 10 inch barrel upper on a lower with a rifle stock.
In general, the standard configurations are:
a rifle gas 20 inch barrel on a lower with a rifle stock.
A carbine gas 14.5 inch barrel on a lower with a carbine stock.
The stocks have completely different receiver extensions, springs and buffers among other parts.
And the carbine stocks/ sized buffers have different weights for different configurations.
Do a bit of searching and reading and it will become clear quickly.
carbine stock would be the adjustable ones (shorter receiver extension than the A1/A2 fixed rifle stocks), they have a shorter, stiffer spring, and a shorter buffer. The standard weight buffer is a bit lighter than the rifle buffers as well.
ETA: too slow