Even though the state of Arkansas has legalized medical marijuana it is still illegal on a Federal level. Since the government still considers marijuana a Schedule 1 controlled substance. That means to have medical marijuana you would have to give up the right to own firearms.
This is a really tricky topic that other states with legalized marijuana for medicinal or recreational use has been dealing with. The Alcohol, Tobacco, and Firearms Agency has stated their position on the subject,
Federal law prohibits any person who is an unlawful user of or addicted to any controlled substance from shipping, transporting, receiving or possessing firearms or ammunition.”
In 2016 California residents were dealing with the same thing, the question was do state legal medical marijuana users have the right to bear arms. The U.S. ninth court of appeals ruled that no, they do not have a second amendment right.
