I would have expected a better showing from Nightforce though.
Not really. To be competitive a scope must posses certain features- Front focal plane, a good Mil reticle, 1/10th Mil adjustments, an upper power range of at least 20x, good clarity/resolution, solid tracking and be durable. The only Nightforce scope that was FFP was the F1 and it is a 3.5-15x50mm. That's why you don't see them in matches. With the release of the BEAST they will probably start showing up.
As for military issued optics-
Marines issue the S&B 3-12x on the M40, the 2.5-8x Mark 4 on the Mk12, and the Leupold 3.5-10x Mark 4 that comes on the M110. The Army issues the same Leupold 3.5-10x Mark 4 on the M110, the 34mm tubed M5 6.5-20x on the M2010 and the 4.5-14x Leupold Mark 4 M1 on the M107. SOCOM issues Nightforce, S&B and the new Leupold Mark 6 3-18x just won a contract.
What's important to understand is that the only scopes that have won a straight up large open competition are Nightforce and S&B. All of the Leupolds (excepting the Mark 6) that are issued are there because that is what the manufacturer of the weapon submitted. Not because they were tested and beat any other scope.