These two posts are giving two different answers... Unless you think adding a muzzle device to a CMR30 is enough to make it NR??
The common thread is that it makes no sense.... and apparently that's ok with the folk in charge.
The lack of consistency that we have seen from the RCMP lab when it comes to classifications is just another example of how dysfunctional things are.
If some brainiac decides that a certain length makes a gun safe then who cares how it's made that way? Ok I could see a requirement that the part added be permanent as was the case with the M1's... but even that was not accepted?
It's all so silly and just more fuel for the bonfire when it comes time to simplify and re-write the book.