I don't switch barrels on my Sauer 200, but the 202 owners I know say they hold zero and shoot way under a MOA with both calibers.
In fact, one of them says both his calibers shoot to zero, with no adjusting of the scope settings when he changes.
The SIG SHR970 is a way inexpensive way to get into two or three barrels on one rifle. I have a .308 and a .280 Rem, with a .270 Win barrel which I had picked up long before I found the .280 so cheap in an estate collection. To change from, say, .270 to .300 Win Mag, you need to swap bolt, magazine and barrel. For .30-06 to .270, .280 Rem or 7x64, just the barrel.
The truth is that, if you can find a way to protect the trigger in packaging, you can just remove the barrelled action from a stock, especially a composite one with glass bedding, put it back and hand tighten the screws, and it will hold zero. I watched Kenny Jarrett do it with a rifle he had built on a Rem 700 action, taking it in and out of the stock over and over, shooting bullets on top of bullets at 100 yards.
The Browning BLR comes as a takedown version, and barrels are only $279.00 retail. They shoot like a bolt action. They are a bolt action, with a rotating lug lockup, operated by a lever instead of a bolt handle. Huge selection of short action, long action, magnums and short magnums.