Sanders is Mr. Confiscation about most things. Land, IRAs, Savings Accounts over a certain amount, Paychecks over some arbitrary amount, Capital gains from investments, Farms, Factories, Banks, All media outlets, etc.
Guns are just one thing on a list of dozens of things that Commie Bernie believes should be State property. His policies are modeled on the old failed Soviet Union, word for word, and step by step.