your DON'T relax the shoulder. the butt stock is held close (tight) to the shoulder.
In this manner there is less (pain) recoil to the shoulder.
30/06
Uses .277 bullets
Generally speaking, no. You can only fire the caliber for which the gun is chambered. There are some exceptions, but not many.
All of them.
No.
You will have to tell us if you are talking about black powder or center fire.
A .222 is a .22 cal center fire weapon at fires a .222 round
It fires a 7.62x51mm NATO bullet, which is similar to a .308 Winchester.
I Sold mine for 100 dollars
The Olympic air pistol and air rifle events use a .177 caliber pellet. The biathlon (skiing and shooting) uses a .22 caliber rim fire rifle.
You aren't supposed to dry fire .22 rifles because they are rimfire. If you want to do this, you need to find some .22 dummy rounds.
100 USD or so