The NFA model has a bbl under 16" OAL and the moderator can be removed.... on theNON NFA model the moderator is welded in place and provides a BBL length of 16.1" OAL. The moderator is a replica only on both NFA and NON NFA models, it does not reduce the DB rating or act as a suppresor in any way. The original moderator made by Colt only reduced the DB rating by 3-4DB so there really is no reason to pay a $200 tax on an item that doesn't really provide a reduction in the sound rating. The original moderator made by Colt was primarily designed to reduce the the sound level to that of the Full size M16A1, an added benefit was the increased back pressure that aided cycling... the down side is the Colt moderators fouled easily. The easier and better soulution was to open the gas port as is done on the current sub 14.5" bbls.
I only sell the uppers as complete units. I will sell the stocks separately....$225 for the complete stock assembly.