AR buffer tube and spring

[bodiebill]

Building an AR15 from components.
I have a FAB Defense adjustable stock and need the appropriste buffer tube and spring ***.
What len gth buffer tube.
How does the FAB Defense butt stock retain on the tuve?

[RickRyder]

This video answers just about all of your questions. http://www.youtube.com/watch?v=PvcznfgvW3U

As far as the buffer tube, apparently you can use either a mil spec or commercial diameter tube. As far as the length, just go with a carbine buffer tube. A rifle tube would be for a fixed A2 style stock and a pistol tube won't support a butt stock.