1914 dwm

[Ron Wood]

Rich,
The frame serial number is stamped after finish sanding but before bluing. The barrel serial number is stamped after bluing or “through the blue”. The upsetting of the metal around the barrel stamp results in a change in the top layer of oxidation (the “rust” of the bluing process). The microcrystalline oxidation flakes off over time resulting in the halo effect.

David,
The halos do look quite uniform and raise the suspicion that they are the result of micro-blasting. However, looking at a magnified image, the indentations on the halos, particularly on the left side of the “9”,”1” and “4” and the “tail” on the “b” would seem to be correct. If someone can control micro-blasting to that level of detail, there is no hope of detecting forgeries.