A while ago I traded a normal am/mm rail for an "undrilled" am/mm rail. That means that the hole for the foregrip is not drilled all the way through. It is drilled from the top, but the hole was not completed, it does not go all the way through the rail. Looks stock, as part of the hole is powdercoated.

Is there any rarity to this, at all? Or can I just finish drilling the hole?