Friend of mine saw an old double-gunsmith in Savannah do that, Chuck, by swinging the barrel set overhead and downward, like a sledge hammer, onto a couple bags of lead shot. He let inertia bend them until they looked like he wanted.

CZ, I straighten shafts for machinery on the farm often using my 20 ton hydraulic press. I know what you mean by "rebound" exactly. I once did a back axle for an employee's high performance four-wheeler. Got it so true by eyeballing it that he couldn't even feel it anymore at 70 mph.

SRH

May God bless America and those who defend her.