If the president or one of his subalterns issues an order infringing the right of firearm ownership would a writ of mandamus be the proper remedy to stop him? This type of writ I have been told is used to order a public official or agency to perform a duty required of them or to refrain from an illegal action.

Patriotism (and religion) is the last refuge of a scoundrel.

Jesus: "Take heed that no man deceive you."