After soaking up some info here, I think I have my build plan figured out.

1. Buy stripped lower receiver.
2. Buy lower receiver parts kit.
3. Buy buttstock assembly.
4. Buy complete upper.
5. Presto, AR-15.

Many questions:
-What is the best reference for assembling my lower and buttstock assembly?
-If I mix a RRA lower with a bushie upper will it look mismatched?
-Is the BM name on the upper?
-Would the finishes look different?
-Would the different upper and lower be a good fit?
-Looking at the adco website and doin a little math, it doesn't look like i'll save any money by assembling the lower myself vs. buying a complete lower. Am i missing something?

thanks!

Yep.  Of course, there's 3a. Assemble.



For assembly, I used the one on this site for my first lower assembly, it was fine.  I later read the Walt Kuleck (sp?) book about assembling an AR15 and found it slightly more informative for my later builds, but both work great.

I have a Bushy lower with a RRA upper.  I can't spot any color mismatch except in sunlight and that's expected -- not all uppers and lowers match, even on production rifles.  The barrel may have a BM stamp, but I'm not sure on that.  Fit is likely fine.  I have a RRA lower and a RRA upper purchased at different times that just won't quite close, so it could happen with anything.

No, you're not missing anything, but that is suspicious.  An assembled lower necessitates and additional tax to be paid, so you'd think the unassembled would be cheaper, but it's not.  You only gain the confidence that it was put together right and any burrs or other imperfections that cause an issue were taken care of by you, the operator.

Actually, assembling is better because it gives you the chance to put in that RRA NM trigger.  Which, is very, very good.

Enjoy,

-dan

If you're assembling the lower yourself then i'd take a look into buying just the parts you want.  For example if you buy a lower parts kit and decided to put in that RR trigger that dan mentioned, and an ergo grip and maybe an A1 stock then you're going to throw away the parts you didn't want (well actually use them on your next build but you don't know that yet).  

Thats the beuty of building lowers or uppers yourself you can build exactly what you want.  Plus of course you actually understand how the bolt hold open and trigger disconnector actually work.

All the instructions you'll ever need to assemble a lower are right here

[url]http://www.ar15.com/content/docs/assembly/lower/[/url]

I've looked into buying some seperate lower parts...I had a trigger, hammer, disconnect and their springs...the total for the individual parts was actually higher then the parts kit....go figure.

Thanks guys! Two more for  ya:

The best place to buy a complete bushmaster upper is:

Also, i've heard some mention that there are "old" and "new" RRA lowers floating around and the new are more desireable. Any info on this?