You can change the barrel in 10 seconds without using any tools, just your hands. You need to switch the barrel to use the arrows but the arrows will be in full view??? I am not sure I understood this one. I don't have one here to see and I don't intent getting one but it looks interesting. When you switch back to the caliber you chose, the pellet should hit we're you zeroed before removing the barrel.
It takes either 400 or 500cc
If I hear anything from Theoben or Daystate or any other manufacturer I will share it too. Frederik fortunately is very approachable friendly guy.