Something could be in the way. Check the chamber and the face of the action where the locking lugs slide into place when closing the bolt. Also make sure your firing pin is cocked correctly. It’s possible the shroud and firing pin are off a 1/4 turn and not timing up correctly. Post pictures here or watch a YouTube video on model 700 firing pin disassembly.
As jester896 asked have you changed the scope, if so checked and see the scope base screw is not to long and going to fore in and the bolt is hitting it . Sold one a while back and they call me and said the bolt would not close, i know it was working before they got it. they added a scope they started out saying some was wrong with rifle. , when I checked it in front of them, found they had used a screw a little to long and the bolt would not close it was catching on it , backed the screw out and it worked, told them to get a shorter screw. They did not what to say at this point. Just my 100 cents jj