The Ruger factory will install a factory 7 1/2" barrel. They will install any barrel length that is a factory standard. Go on their web sight, e-mail the shop with all the work you need completed and they will be able to give you a price. Send the gun and wait. You will have to pay for a re-blue. P.S. I hope you let the "gunsmith" that destroyed a good barrel know exactly how pleased you were with his work! Send him a copy of the receipt from Ruger and ask him to reinburse you. He won't but I'd do it anyway. Good luck............Mike