Hi all...

  I’m new to Ar15's and building my first AR. I just picked up a Black Rain Ord. milled Fallout 15 stripped lower (Black Anodized). My next purchase is going to be the stripped upper. I’m having trouble finding the matching upper from Black Rain and I noticed on the Black Rain site the upper is marked as .223 but I want to go with 5.56. Can anyone recommend a good upper that will match my lower with a nice tight fit? A barrel recommendation would be great too. I want to with a 16 or 18 inch barrel and I’m clueless when it comes to the twist rate...

The upper does not need to be marked.  VLTOR has nice uppers, but there are so many nice ones it is really a matter of personal preference and color match.

Twist rates are important for the bullet weights you want to shoot.  Also get a 5.56 or Wylde chambered barrel so you can shoot commercial .223 or mil surplus 5.56.  1/7 twist is Milspec and allows you to shoot 72 grain bullets with ease. 1/9 is common now as well to shoot 55 grain bullets well.  It really depends on your plans.  I have a 1/7 and a 1/9 and they both shoot great.  1/8 splits the difference.

1/7 means the bullet will make one full twist for every 7 inches it travels down the barrel.  

If you plan to do a lot of hunting 18" may give your touch more accuracy over the 16, but they are all good out to around 600 yards typically pretty easily.

Hope that helps some!