Thanks, guys.
I should add that I had only fired 40 rounds through this rifle before, and only to zero the sights and then test at 100m.
I sat in my living room watching the first season of 24 and sorting through rounds. I had a pile of about 35 that didn't make the cut, and put them into mags just as a "maybe these will be fine" and shot all of them without a single problem. They were pretty corroded, and a couple had small dents in the cases, but they all shot to the point of aim, and you should have seen the pile of brass!
We finished the night with 1911s, and I shot about 500 rounds through my SA Mil Spec without failure as well. (I only have 25 7-round 1911 magazines, so that took a little longer, with two of us reloaded mags for three 1911s while the other guy shot. Grand total for the night was 1700 rounds of 5.56mm, 600 rounds of 9mm, and 500 rounds of .45ACP.
The score? Sailors: 2700. Spraycans: 0.