Keep reading, you'll get there.
I think that what we're getting at here is that the cartridge most probably has enough umph to take an animal out towards 1K.
The major consideration is the impact of the environmental condition on the bullet as it works its way to that distance. Time in the air (rainbow trajectory), ballastic coefficient (Short fat bullet), changes in shooting altitude (Density of air), Temperature (Density of air) and wind conditions are major considerations.
Gravity is constant so when you get the drop chart right its pretty much always right.
A heavy bullet with a good BC and some velocity will usually be the good performer.
I'd be for tuning up your current rifle, add a long term scope (as top of the line as you can afford, or save until you can) with target turrets and dive in a do some shootin'. You'll learn quickly enough what you will want your next step to be.
Good luck, have fun and shoot alot. It's the only thing keeping the economy going at the moment.