Well, to be honest with you I hope no one ever shoots at a deer at 200 yards. I've been hunting for a while now (years) and I shoot a 7mm. Even though that gun is capable of dropping a person at 1000 yards, I don't feel comfortable shooting at a deer no further than 100 yards but that is just me. I've seen alot of deer wounded and have had my hunt ruined by ignorant hunters that think they are a sniper in the movies.

But to answer your question, my father-in-law has a bullestics book and according to the book there a few guns tested. a .243, 270, 3006, 7mm and a 300 mag. They were tested with the best ammo for the gun. What I mean is the "best" ammo for that particular caliber of gun was chosen. They testest accuracy from 20 out to 500 yards and power ( i believe it was pounds per sq inch) To make a long story short, the 7mm was the best overall choice with bullestic silver tip shells. It was the flattest shooting, and at distances of 500 yards it was more accurate than the rest, it didn't have the knock down power of the 300 at 500 yards but it was pretty darn close. Before I knew all this, I bought a 7mm, what luck!!