Dale:
I was taught since the mid 50s by the old elk killers there's only ONE shot on game.
That's a double lung shot as Mc. said. Nothing else. Forget the heart shot, it's too small and nearly impossible to hit without very precision shooting and then one side or the other will almost surely hit a foreleg and ruin meat. Besides that, the heart is very good eating, so why ruin it?
There's only one answer to those guys that: "ruins too much meat". What the H are you doing shooting the meat anyway?"
.243 on deer, or antelope are very good, but, close to minimum. Use 100, or 105's and precision shot placement thru both lungs.
That's: Up close to the back edge of the shoulders, I try to aim center height. That way IF/when my range guessing is off some. There's room for high, or low.
I use a 700 with 100gr, 35gr 4895 myself. Somewhere around 2950-3000fps. Would have to spend time digging out the chronograph records to name it closer.
Practice, practice, and then practice some more. When you can keep 'em all on a paperplate no matter the range, you've got it right.
Good luck,
George