Early guns that were sent back to Remington had a center punch dot added between the OU and the serial number, which makes it a little crowded. Later guns that were built with the modifications had the dot included as part of the serial number, so it is not crowded in. Early guns had two pins through the action, but the modification eliminated the need for one of the pins. Frames in process that had already been drilled for two pins got dummy pins in the extra holes. After all the two pin frames were used up, there is only one pin.
