Thought there'd be more of us, here's one lonely vote for the AR. My A2 has a target barrel, is spot-on accurate. It's more versatile than most of the larger calibers mentioned here, and it's the rifle I have the most experience with. Learned to depend on it when I had my government job some years back. It would be tough leaving my Garand, Lee-Enfield SMLE, or Winchester lever guns behind, but you said just one.