[drift] I am considering a build. I have intermediate skills with tools, I used to work on cars until the computer crap came along. I have lots of tools and access to others, but, I'm really a tote and fetch, dig that trench, haul that barge kinda guy. I would want to do one in .308 Win. Are there any special tools I might need? All the reading and video's on the web make it look easy. Probably a lot easier than it really is. [/drift]
FBG, If you buy the upper with the barrel and fore-end already attached, I don't think you even need a screw driver to "build" and AR.
Okay, yes you do. To attached the grip I think there is a machine screw. Assembling the trigger mech does take a little paying attention, but no special tools (a punch set can be helpful but not necessary).
Actually mounting and zeroing optics might take more effort and tools. Now if you buy the barrel, gas block, upper and fore-end separately then some tools will be needed.