I am planning to purchase (or convert) a SIG556 sbr. So, let me first & foremost, state that I AM GOING TO TAKE ALL THE NECESSARY STEPS WITH THE BATF. I've dealt with them before when getting a suppressor, so I am aware of what needs to be done.
I basically want to make sure that I am on the right track. Here is what I'm planning on.
*I want to purchase a P556 SWAT (pistol) and add the folding/collapsible stock that comes on the classic 556.
I have read multiple times that the ONLY way to achieve this is to buy another 556 and swap out the lower recievers. However, I called SIG yesterday and found out that they actually sell the desired stock for a mere $72.
Here is a picture of the stock I intend to purchase:
What I now need to know is what else will I need to do to add this stock to a P556 SWAT.
I plan on getting a special tool to remove the butt plate on the P556. Do I need to buy a buffer tube or a hinge? Is it really this simple?
Also, how am I supposed to know the complete length of the gun (for the FORM 1 BATF) before I have all the components?
Any help would be very much appreciated.