Try;
modernballistics.com
Its an extremely useful program for answering a lot of different "what ifs". You just need to know your MV and BC, but there are several cartridge loadings already in a database. It's one of the most versatile exterior ballistics programs around, designed to be used in the field as well as in the studio at home. Though it will take you some time playing with it, you'll enjoy it.
One thing you learn fast; At longer ranges, BC matters a lot.