Hornady Ballistics Calculator
I use the Light Magnum Ammo, now since re branded. Once and done on every deer I ever shot with Hornady and they all dropped in their tacks, no trailing required.
Here is Hornady's free calculator:
Remember the 343
George Johnson, Ladder 157
Dan McWilliams, Ladder 157
Bily Eisengrien, Rescue 2Scott Strauss NYPD ESU