Try this...
Push into the pile low and crowd the bucket as you lift and curl back to fill it in one, fast motion. Then, as you are backing out of the pile, lower the bucket to the ground by slapping the joystick into float and quickly pop it back up a couple inches. With the bucket in this position, low to the ground, drive backwards to the dump site as fast as possible. The bucket will act as a wheelie bar/skid and you can go a heck of a lot faster with a full bucket in reverse than you can forward. If you do it driving forward and the thing starts bouncing, the bucket can dig in and suddenly stop you. By going in reverse, the bucket will drag over anything and you will hardly notice it.
If it takes you one minute to load the bucket and scoot backwards 600 feet to the dumpsite, it will probably take you the same to dump it and scoot back to the loading site. So, to be conservative, plan on 2.5 minutes per round trip. That's 24 trips per hour @ 2.5 yards per trip, because you can get more than 2 yards in a 2 yard bucket when it is heaped. That's only 60 yards per hour on a best case scenario.
In 8 hours you should be able to move 480 yards of material.
In 40 hours you should be able to move 2400 yards of material.
How much material are you planning on moving and is it already in a lose pile?