Based on some apparent inconsistencies that appear in the photo, it looks to me as though the barrel engraving might have been lightly welded and then scrubbed?
I marked up a copy of your photo. There are mottled blue-ish sections that might have been discolored from welding along with some pits where the engraving should be? It looks different enough to me to indicate a carefully reworked surface.
Look at how smooth the contoured section of the barrel is below and around the serial number, then look at the rest of the section I have marked in gold.
I certainly could be wrong, but I don't think so, at least based on your photos and the rest of the Russian markings scrubbed.
Hope this helps!