Can always un-bow the barrel. Somthing of large diameter, solid, but soft enough to not mar the barrel. There is an ancient, lightening struck, pecan tree trunk crotch in my back yard that is perfect. Firm, gentle pressure, lots of checking aganist a daed flat surface, and you can get it to be visually straight.
Which may not do a damned thing for accuracy.,...but it may help consistency.