This cool kid's 700 SVS Varmint is a .223
If you're shootin' paper and maybe varmints down the road, .223, I'm voting. Quieter and softer will make you a better shooter, too.
The .223 price advantage isn't a hefty margin if you compare apples to apples ammo by mfg and type, like match load to match load in these calibers, but it's there. You will get a little more shooting on the same dollar. Another plus in the .223 column.
While I have the Varmint model, I like your choice of the Tactical. I think it has the 1:9 twist rather than the 1:12 mine has, so it will do well with a heavier bullet. I've been shooting Black Hills 52 grain match in mine and could go lighter, but I think yours will like that weight on up to 68 grain. I've been shooting those same rounds in an AR with a 1:9 twist and it likes that weight also. For that matter, I've had good luck and good groups with Remington UMC, 55 grain mc, (fmj) @9.99/20 rnd. I haven't tried any of the hot little 36 or 40 grain loads but that's on the agenda - just to see.