Great rifle. The sight bump is a variable. Many believe they damage accuracy but some bed the bump and use the screw to snub the barrel down. This will tie the pressure on the barrel to the wood forearm, not a great idea for a hunting rifle sure to be exposed to the elements.. I would put the screw under the butt plate (for safekeeping) and float the barrel, just a bit! Of course the action should be bedded first so that the action is dead when the screws are removed or inserted. then the barrel can be floated until a dollar bill can move the length of the barrel except for a few inches of the barrel reenforce. Taken care of the rifle should last several lifetimes. Of course the memories it will carry will make it priceless.. For a deep cleaning I use carberator cleaner. The cheapest you can buy a walmart. I believe it's 79 cents a spray can. The spray tube allows exacting control and a brush to loosen the really sticky stuff. Be certain the stock is off the metal and re-oil immediately as the metal will be absolutely bereft of any oil protection. The sticky bolt action is likely due to congealed grased etc. in the locking lug recess.. Clean this area thoroughly! The bolt should have a little dab or grease behind each lug and on the bearing points of the trigger assembly. wipe the bare metal down with a light coat of oil or spray with RustPrevent which is a product that leaves behind a coat of wax to seal the metal surface. It is the best protection I've found for stopping rust. The M70 action works very well and unless the mag spring is weak, all should be fine,,good luck!