I doubt you would ever see rifling impressions on a new rifle as the boring is done more precisely and the mono bullet is not obtured(sp)in the bore. I have spoken to gun makers, Barnes directly and gunsmiths to come to my conclusion. However, I have seen these impressions on a vintage DR on a visit I made to Champlins. When held up to the light you can see a ghostly image on the barrels in the pattern of the rifling.