I went to my local B5 in early January, I was shocked to see they no longer had any of the GSG-5, HK MP-522, HK 416 22's or the Sig 556 22 on the shelf. I asked the manager if they still carried them. He said they had them but don't display them because some of the local citizenry were making a stink that Big 5 was selling "assault weapons". But they did have them.
Not sure of inventory lately cause I haven't checked. But they don't display them still, they might actually be out of stock now.
They still have ammo though.