Read up on "switch barrel" bench rest rigs. There are guys that have modified Rem 700's and Savages (basically pin the barrel nut to the barrel) with flats on the muzzle end of the barrel to let them wrench on and off the different barrels. Nice part of doing it with a Savage is that you don't need a complete bolt ($200ish to do it with a Remington where you need an entire bolt), you just need a bolt head. With a Savage, you can either pin the barrel nut, then torque the barrel/barrel nut onto the action from the muzzle without removing the action from the stock, OR, you can leave everything alone, pull it from the stock, pull the barrel, and replace it. All you need is a Savage barrel nut wrench and a set of go and no-go gauges to set the headspace.
The difference in this and doing your own barrel installs is that the headspace in the barrels has to be set, then the barrels can be removed and replaced at will, just by monitoring the witness marks, or torque setting. The challenge with buying a new barrel and doing your own barrel job is that, for other than "barrel nut" style rifles like Savage or Mossbergs now, you'll need a lathe to set the headspace, or get the chamber cut shallow then hand ream it (which can be hit or miss, depending on your technical ability). I had a Rem 700 switch barrel rig in college. Flats on the muzzle and a custom wrench. I had gunsmiths install the barrels the first time to headspace properly, then make witness marks on the bottom of the barrel to match the action mark and note the torque. Then I could remove it and replace it myself.
Savages are super easy to DIY, but it does require that you remove the stock, unless you pin the barrel nut, then it basically behaves just like any other threaded barrel.