There are a couple ballistics trajectory programs that work very well, if you have a 100 yard zero, know the scope height, the muzzle velocity, and the bullet's ballistic coefficient.
The two links I'm going to give use the same core program, but the first uses a bullet chart to reference the drag coefficient (B.C.) If your bullet's on his list, it's dirt simple to use.
http://bisonballistics.com/point_mass_calculations/new
If your bullet is not on his list, the JBM calculator will do the job, as long as you've got the B.C., or a very close approximation,
http://www.jbmballistics.com/cgi-bin/jbmtraj-5.1.cgi
More than once I've gone to a 1,000 yard match having set up at 100 yards using these programs. The first shot was on the paper.
Another edit: Guess I should have added: set the program for a 1,000 yard zero. That's what the chart should show. Now glance up the chart to see how high your bullet strike will print at 100 yards
The only problem with Jim 1K's "23 inches high at 100 yards" is he doesn't have the scope height -- I guess that's it. I've a small 6mm, and with the bullets I use (106 Clinch River), I'm about 27 inches high at 100 for a 1,000 yard zero. I use 3,025 fps with a B.C. of .520 & a scope height of 4 inches -- that is unusually high, I know.
The recommendation to shoot at something in the dirt nearby is a good one. It takes over a second for the bullet to go to 1,000 yards. Plenty of time to get back on the target through your scope & see the splash. Now put your scope back on the original aiming point, and without moving the rifle, turn the adjustment knobs until the crosshairs center on that splash. Next shot should be better than "on target."
P.S. I too don't think the problem is with parallax.
Remember too that if this is a match, the paper of the IBS 1,000 yard target is 42 inches square. You can hold at the top of the paper (repeatable aiming point) and get another 24 inches of paper to print on. Then there is the top of the frame, another repeatable aiming point...
Edit:
Remember also that "parallax" can be thought of as mis-positioning your head. If you pull your eye back so you're not using much of the scope -- you cut any effect of parallax by the same amount. Even a blur shouldn't hurt too much, far as getting on paper. In fact, over half my IBS points came from a time when everything was a blur. "The center of a blur is still the center," I use to quip... Real old man glasses helped with that.