Collapsible Stock

[Glenzo]

This will be my first attempt at building an AR. The complete lower from Arms East looks like a good place to start.
My question is, are the collapsible stocks still available? Marstar, Questar and Arms East do not seem have them on their sites. Can they still be purchased or are they now banned?

 

[(Ronin)]

They are still around..
Just not easy to get like they used to be.
And don't use the B word..it's too British