I have looked all over and cant seem to find an Ar-10 upper in .308 with a heavy target barrel 24 to 26 length . Any one know of one for sale ? Preferably new . I guess I will have to make my own from parts if I can find a decent barrel .That seems to be the hang up for complete uppers . I see Criterion barrels mentioned but they don't show them on there own web site and the heavy contour is 1-12 twist rather than 1-10 .I wonder why the slower twist ? Arnie