Hello all, looking for your help on something. There is a sbr on gunbroker currently I would like to purchase, but make it into a rifle by adding the 16" barrel. All the barrels do is screw in and out so easy swap. I'd leave it as is, but an sbr is a no-go here in NY. Am I correct in thinking that all that is needed is the current owner just decertifies it, doesn't include the barrel, and now my ffl accepts it in their books as a rifle?

Something tells me this is gonna get complicated

Edit:
Receiver was purchased originally by itself, then the parts were added creating the SBR. This did not start out as anything but a bare receiver.

if it is not in an SBR configuration its not an SBR.....regardless if its on the registry or not

This, however if it has no barrel at all attached then the FFL should transfer it in as an "other firearm".  Without a barrel, it can't satisfy the definition of a rifle, much like a stocked AR lower without an upper is classified the same.

Still gets it out of NFA regulation, but don't know if "others" have issues in NY vs. a "rifle".

Correct.  This only really comes into play next time somebody goes to SBR it.  If the ATF examiner sees the same gun is already a registered SBR, it can throw a wrench into the process.

In NY you also have to make sure if it's a semi auto with a detachable magazine that it doesn't have any of those "evil" features