bob- smaller rifles tend to do things like prairie dog shooting. so, especially for hot-rod cartridges (243, 220 swift, and my personal favorite - 22-250), it is possible to burn a barrel out in a single outing.
also, many people don't know how to respect a rifle... so, the smaller, less recoil cartridges tend to get shot more - which is fine, except i doubt many people will let barrels cool.
because the 30-06 is a very mild cartridge regarding barrel life, and because it does indeed produce enough recoil out of a bolt gun to be unpleasant after a couple dozen rounds, it is highly unlikely the thing has been shot enough to reduce its useful life by much. contrast that w/ a 223 where after a couple hundred shots, many shooters still don't notice the recoil - and how long do most people actually shoot for (shots/hour) - and you can see where that's going...