Ant,
I don't know about all of the internal differences between the two, but the tactical scopes typically have different reticles, plus different internal gears and knobs and things that matter to tactical shooters, which I am not. I also believe it is a 30mm tube, not a 1 inch, but I don't know. Tom's gun is listed just below this thread as "carnivore".
I have yet to take a game animal with my gun beyond 100 yards. The two elk and 1 deer were a little too cooperative. As for target shooting, most I've ever experimented with was to 300 yards. I do most of my load development shooting at 100 yards and have only had the gun up and running since last September.
One other thing, I wouldn't recommend a muzzle brake, they just don't kick enough and if you are going with a heavy barrel, that should really kick the muzzle rise down. Might also consider some sort of heavy target stock if that's what you're after.
