Do you handload? A 30-30 could make an interesting option if you handload, the 45-70 is always interesting, handloaded it is possible to do anything from 45 ACP to all your shoulder can take. The 30-06 can do everything from 30 carbine to stepping on the heels of the 300 Win Mag. A lot of good bullets are made for the 30 caliber. If you have the 7-08, I see no point in the 308, but he 280 would give you few hundred feet per second, if that's actually usable is another question. The 357 or 44 Mag barrel could give you some short range plinking options.
Perhaps a better place to start is with the question, What performance do I want my basic battery? I plink with cast bullets, and shoot whitetail deer that are dumb enough to stand there and let me. (If Darwin is right, one day I will not see any more deer :roll: )
My battery is 4 rifles that effectively mimmick one another, with one exception. I have a 30-30, a 357 Max, a 44 Magnum and a 45-70. the 30-30 and the Max a virtual ballistic twins, though with the 30-30 there is a greater selection of higher BC bullets that extend the point blank ranges by 50 yards or so, still they are 150 yard rifles for practical purposes. The 45-70 does well in this same range, but with heavier bullets, but if any of those darned Cape Buffalo ever escape Africa and invade our shores, well let me tell you buddy I'm ready. :-D Finally my 44 is a 150 deer rifle. So with four ways of getting there, I'm gonna add a fifth, a 38-55. Same song, another verse. My battery has nothing to do with logic, and I don't think any other shooters does either. But asking the question gives us the chance to justify yet another firearm. So I think you should purchase not 2 but three barrels, two you want and one for the fun of it. I bet the third becoms the on you shoot most.
