I would recommend that you not extend the chambers because these barrels narrow down very quickly and you will be removing valueable steel right where it is needed the most. I advise you to look for lighter loads for the rifle, not heavier or faster. Even though your gun is comparably newer than many out there, it is an unknown quantity when it comes to strength, eapecially since you are not dead sure what ammo it is really supposed to take. Do not refinish it, restock it, reblue or otherwise mess with it. You have been extreemly lucky to be able to purchase this gun in the extrordinary condition that it is in. Anything you do or have done to change it will make it worth less and will look wrong. Leave it alone! That's my two cents worth. Bob H.