Heck, the FN factory that built Browning Auto 5s had a barrel bending rack, jig, and window with grid paper on it….just for straightening barrels before shipment. They used rods, and hand bent the barrels to true.

FWIW, there’s tons of ‘shotgun people’, that are REALLY just wishful of being considered ‘shotgun people’, that get wrapped around the axle of stock ‘fit’ vs POI as if it’ll make them into an international champion…..all the while never even noticing that their barrel doesn’t shoot to POA to begin with. I’ve seen it, and heard of a lot of error compounded by trying to fit a stock to a POI, with a bent barrel or out of square choke threads. POA/barrel true has to happen first. I’d never take a barrel OUT of true, either. It’s the Indian, not the arrow.