Sounds like you just got one of these as well?
I will shoot the beast before sending it off to PK, if for no other reason than just to see how much better it works on its return.
I hope PK will see this and wade in on the WH M1A1 bolt question. I understand that the WH bolts can be badly out of spec. Just holding the WH and Savage produced bolts next to each other, I can see obvious differences, including that the WH bolt is about 1/16" longer than GI. Then there's the safety question: the firing pin on the M1 bolt does not protrude past the bolt face until the front of the bolt nearly makes contact with the receiver. Cartridges thus cannot be fired by the firing pin when slightly out of battery, as occasionally happens with M1A1 style bolts.
Original parts can be pretty easy to identify; most will have the manufacturer's stamp, generally "S" or "AOC". There were other subcontractors as well. The post war parts on this gun include the sear, trip, and magazine catch. All are rather crudely cast, and have a reddish-purple color, making them easy to spot without even having to look for the maker's marks. The front of the trip where it catches the bolt is especially rough, producing an extremely heavy trigger pull. I would worry about this damaging the slot in the bolt, and so will not try to fire the gun until the WH parts are all replaced with GI, which is easily done.