To find velocity at variouse differences you'll need two more items.
1) The BC (ballistic Coefficient) of the round you're interested in (Hornady & Nosler should have them published on their websites).
2) A decent ballistic calculator program.
Here there are lots of FREE options. Go to [url]http://www.md-ar15.com[/url]
In the Zeroing Methods section (read the text) you'll find two links to online calculators (I'll use the first link occasionally).
If you are a site member (its free & easy) you can download the ones in the Documents section. I have an Excell based spreadsheet and a Palm/Handspring software product that is good up to 500yards.
In general when using a ballistic calculator you'll need the following:
Velocity of the round
Distance at which the velocity was measured
Ballistic Coefficient of the bullet (BC)
Mass of the round (in grains)
In addition for a more accurate chart you'll need the environmental conditions such as the altitude, temperture, humidity, barometer reading when the measurement was taken. This is 'nice to have' info, but for most people its really not needed.