MAK 90 Upgrade: Help with the rules
I just recently purchased a used MAK 90 with several 30 rd Mags. Serial Number starts with 93. It does have a nice flash suppressor on it as well as the thumbhole stock. This is my first imported assault rifle, and I am unsure on the rules. I would like to add a folding stock, some picatinny rails, and maybe a foregrip. Some of the stocks for sale, mention needing US compliance parts in order to be legal. Can anyone explain this to me in Layman's terms?
(can I add a rail mounted bi-pod and be legal?)