Are you sure? 2 seconds is a long time. Get a stopwatch and time it. I've taken many pot-shots at 800 yards and only had to wait about a second to see the results.
Also, that's just the exit-the-barrel speed. It slows down AFTER that point due to the density of the air its passing through.
EDIT: 800 yds is about 2400 feet. If the muzzel velocity is 2800-2900 (and I'm just quoting you here) it wouldn't be exactly one second it would be 0.85 seconds or so.