He was absolutely in favor of the individual’s right to keep and bear guns. Buckley, like Ronald Reagan, Pat Buchanan, William Bennett, Jack Kemp, and George Will, also fell for the “assault weapons” ruse.
Reagan only fell after he got shot and was "guilted" into urging passage of the Brady bill and then I think when he got sick upstairs, he fell into the AWB. But never when he was a strong POTUS. Otherwise, we'd already have seen them banned.