The question was asked "What about creating something that would allow you to use an AR-15 Buttstock on your SUB-2000?"
I agree completely! I wish it was already setup that way. Would have been a much easier option to incorporate that feature into the gun design from the beginning.
The problem is since the bolt tube/receiver is the only serialized part on the SUB-2000 that piece is technically the firearm. We have to leave that piece in place. There is your first design constraint.
So now we have to think about how do we add something to what is already there to make it functional with all AR-15 Buttstocks? We have to look at the AR-15 Buffer Tube and add those features to the SUB-2000 Bolt Tube.
Second design constraint is that the SUB-2000 still needs to fold.
On the SUB-2000 Buttstock there is a cut out to all the front sight to drop into.
Third design constraint is that the barrel and receiver needs to lock into place when folded in half.
What are you thoughts and ideas so far? You don’t need to provide a finished solution just start throwing out some ideas here.