All my larger cal rifles are glass bedded so when I take em apart for whatever reason, they go back together pretty much exactly the same and 'zero' stays pretty constant. Screws need to be tightened evenly of course and I usually do the final tightening to the tang screw first.
Even with a non bedded barreled action gun, zero shouldn't change too much. Yes, it could change enough to miss a long shot on a deer but any rifle should have it's zero checked prior to hunting.
In other words, if you want to give your rifle a good cleaning and oiling, go for it.