I recently asked the owner of a local gun shop about tapping a firearm for scope mounts. He refused, in no uncertain terms, to drill and tap any firearm. He said it is impossible to know how hard the metal is. He has been in the business for a very long time and thus I was puzzled by his response. Is that procedure really that complicated? I understand that it would all have to be aligned properly in a non-marring vice, but to a gunsmith, I wouldn't think this would be rocket science.