Few observations here:
1. that appears to be a red box of 75grn. Hornady TAP
2. the yellow box apears to be 77grn. Nosler bullets (not the SMK)
3. no optics on either rifle (w/ extraordinarily tight groups for open sites at 100 yards)
4. from ADCO's own web-site, it apears they have trouble with the differences between "chrome-lined" and "chrome-moly"....
www.adcofirearms.com/rockriver/rrauppers.cfm?page=rra"pic of upper here"
A2 CAR
chrome lined 1734
$450.00
Complete w/bolt, carrier, and charging handle
5.56 chamber, 16" 1:9 chrome moly Wilson barrel.
YMMV, but I believe there's a difference between chrome-moly and chrome-lined.
Mike
ps - one thing to consider here, dealers w/ 1/9 twist barrels and products in stock have good reason to overstate the abilities of their products.....food for thought.
I swapped all my 1/9 uppers out for 1/7s (2 were RRA uppers/chrome-moly, 1 Bushmaster/chrome-lined) not because they wouldn't shoot the 77grn. SMKs, they shot'em, they just didn't shoot the group sizes depicted above, wereas my 1/7 twist uppers (from CMMG and LMT) shoot knots at 100 yards using factory bluebox BH 77grn. SMKs .