Have to disagree with a a bit of this ^^^^^
First off, comparing the two, it's not even close, a 6.5 147gr ELD @ 2750 fps vs. a .308 225gr ELD @ 2250 fps isn't even a race according to Hornady's calculator. -279.8" to -419.3", I didn't bother with the wind as the 225 is going so slow, I can't see how it would have an advantage, but it might.
*edit* Misread the previous comment, yes .308 has greater selection across the board for projectiles. I've read plenty of accounts of the power of the 160gr RN, I think it's equal to anything the .308 can sling at shorter ranges, my opinion for what its worth. If the .308 case was a bit larger, then it would have an edge, but they are basically equal.
"Savage is crap", I guess if you have unlimited funds this is understandable. Savage is not crap, especially if you get the right model/action. I've never had a Savage that I couldn't get to shoot. I had a Tikka that liked only 35gr-40gr bullets, ALL my Savage Rifles would shoot 55gr-75gr equally well with the right powder. My only complaint, extraction, it can be a bit unreliable, that's the one thing that could get me to pass on one, and only if it was a Rifle that my life would depend on...Bench Rifle doesn't fit that description (forgot, they can have some hideous machining errors, best inspect before you buy). In the end you tend to get what you pay for, but if he can convince the Wife Smokeless Powder good, maybe a gently used older Savage 10 FCP in .308 in a new XRS/LSS XL and a basic reloading set would serve the OP best.
I do agree that 308 ammo is more prolific, but it's a Bench Gun, most likely not an issue. 6.5 CM is so well supported by Hornady and others it's clearly a better Cartridge for Target Shooting, than .308 Win.