Originally Posted by
a0cake
You're going to want to go with a Stainless barrel, first of all. While high quality chrome lined barrels certainly can be SUB-MOA accurate, Stainless barrels are as a rule more accurate.
Second, this is obvious but keep in mind that the best barrel in the world won't make M855 shoot straight.
There is a lot of good factory ammunition out there, like the Black Hills offerings featuring 77GR Sierra Match Kings to name one example. You will likely find that this (or similar) factory match ammunition will shoot under an MOA out of a high quality barrel. However, to achieve maximum precision, you will have to do some load development to suit your unique equipment.
The following is a short list (NOT ALL INCLUSIVE) of just a few places to look at for good Stainless AR barrels. Some of the following are considered Match Barrels, some are high end production grade. Some are cut rifling, some are button rifled. You will need to do your own research to figure out exactly what you need and want (length, contour, etc). I'm just giving you a few places to look. In the right hands, with the right ammunition, all of the following are SUB-MOA capable:
-WOA
-Ranier Arms UltraMatch (From Shilen Blanks)
- Krieger
-Lilja
- Hart
- Douglas
- Bartlein
- BCM SS410
- Noveske