bolt closing?
if you have scope bases installed,make sure the front ones don't have too long of screws(going down into the lug area)and your front action screw isn't too long going up into the lug area,couple of other things,does the serial number on the bolt match the serial number on the receiver,and the roll pin holding the ejector is not protuding out on one side.I had one someone had somehow gotten the tip from a v-max into the lug area,so look in there with a light .
Does the bolt close on an empty chamber,if so disreguard the above info,and look at your die set up if it's not a factory round