speaking of "long term builds" i've got a bunch of parts in the parts cabinet... i just need to toss some LPKs, BCGs and a few lowers and some furniture in there and shake it hard. complete rifles will tumble out.
let's see; complete A1 kit from the rifle i broke the cast receiver on, two middy uppers that need FF rails because the company that built them put the FSB too far forwards (these were a special order back in the early days of middys) so i need two DD Omega rails, two 20" uppers, one an A2 and one a DCM HBAR have A2 HGs for them now, but a rail for the HBR wand a MOE for the A2 would be nice, all those have flattops, the 20"s need optics and BUIS, everything else has DD or Larue BUIS, then i have a cheapie 16" barrel with an A1/C7 upper, and a SS bbl with a flat top.
have one rifle that needs the A2 upper receiver swapped for a flattop.
and *several* complete rifles.
and the latest is a S&W 15-22. of course i got one of the last ones before they started shipping the versions with the flashhiders. VERY nice, just needs to get the muzzle threaded, but that's purely cosmetic. there's just no NEED for a FH on a 16" .22
lots of long term stuff going on here. unfortunately it's not going anywhere fast because i'm recuperating from eye problems and still trying to get back to work. can't aim anything right eyed any more since i have no lens on the right now. have some .308s that i can't really shoot any more that i need to sell. 2 HK91s, 2 Rem bolt guns. if i can move those that will help pay for other goodies.
however, if i didn't have all that stuff floating around and as starting from scratch, i'd be looking into complete upper and lower halves from DD or Bravo.