Steve,
I did an article on reboring a year or two ago, and interviewed some reborers. Dan Pederson suspects that along with the quality of a new cut-rifled bore, the reboring process also provides some more stress-relieving to the barrel steel, thus potentially improving accuracy in another way.
One of the barrels he rebored for me was a factory button-rifled barrel in 7mm STW that never shot very well at all, no matter how many handloading and rebedding tricks were tried. Dan rebored it to .358 Shooting Times Alaskan, and it became VERY accurate, despite the much larger bore, which had to reduce stiffness.
I suspect a lot of shooters who refuse to try rebores somehow equate them with retread tries.
