is it cocked?
cause there are 2 stages to those old cooey bolts.
1) the bolt is closed
2) the bolt is pulled back and cocked
if your in stage 1 then just open the bolt and take out the live round.
if your in stage 2 then point the rifle in a safe direction and grab the back of the bolt with your thumb and finger, hold it firm, pull the trigger and that will release the bolt and you can just softly bring the cocked bolt back to stage 1.
then just open and take out the live round.