According to VLTOR the VLTOR A5 buffers can only be used with VLTOR A5 buffer assembly components. So it will most likely not work with the Geissele Rifle Length Spring, 42 in. However, I recommend contacting VLTOR to confirm.
This Geissele Rifle Length Spring is a rifle length spring designed for rifle length buffer tubes. You would need a carbine length spring.
The Geissele Rifle Length Spring, 42 in is compatible with Mil-Spec rifle length buffers and will not work with carbine length buffers.
Yes, the Geissele Rifle Length Spring will work in an AR10 chambered in .308.
Yes, the Geissele Rifle Length Spring, 42 in is designed to work in rifle length buffer tubes.
Yes, the Geissele Rifle Length Spring, 42 in should work fine with the VLTOR A5 buffer tube system.
Yes, the Geissele Rifle Length Spring will work with an A2 stock.
This Geissele Rifle Length Spring will most likely be too long. The spring listed at the link below will work.
https://www.opticsplanet.com/strike-industries-ar-carbine-flat-wire-spring.html