To the OP: Here is a very simple question, as you own this rifle and all we can do is read what you type. Have you shot this rifle using 300 Win mag ammo since it's been in your possession and are you sure of the manufacturers date using the serial number you stated? If you haven't, DON'T shoot it until you have the chamber cast or can be 100% sure of what you have! There is no way that entire rifle existed as you now have it if it is chambered to 300 win mag unless it was rebarreled/rechambered to that caliber because that caliber was not introduced until 1963. It is either an older H&H caliber if you have never shot it, or has been rebarreled with the stamp on it and for the reason I mentioned above. Please follow up on this very important and serious matter and get back to us with the results. Thanks and looking forward to a definitive answer on what you have!
EDIT: I checked and the serial # does fall into the 1955 manufactured date. That takes care of that part of the equation. Now you need to answer or do what I mentioned above.
Last edited by Topgun 3006; 01-22-2013 at 11:10 AM.