Well, tongue in cheek or not, there's precedent for it going back a long way. Springfield Inc. has been doing it for at least 30 years to use USGI barrels on new receivers. Folk pay extra for those GI barrels!

Since I had a factory peened barrel ("Geneseo, Ill." marked, even) handy here's photos:







It barely shows the individual hammer marks even blown up this large. A bit more noticable underneath, but you get the idea.