While bad headspace can result in a kaboom, chances are 99.999+% that it will headspace just fine. I have headspaced many rifles/bolts but have yet to come across one that didn't make the cut. The barrel assy or bolt would have to be screwed up from the manufacturer or either/both be hideously worn, and I mean WORN.
You can use the same bolt bottom line. If you are worried about strange wear, just make sure you start with the uppers clean, then check for abnormal wear, metal shavings, etc... These you would only really get with strange bolt CARRIER wear, and I assume you mean using the same bolt AND bolt carrier.
Remember that the headspace is set by the barrel manufacturer so if it's out of spec, not much you can do about it, and they are checked at the factory. A business that put's out bad headspaced barrels (barrel extension acutally) would suffer severely at the hands of lawyers in short order.