Because they would have been arrested immediately otherwise
Federal prosecutors took two weeks to present their case, finishing with a display of more than 30 guns seized after the standoff. An FBI agent testified that 16,636 live rounds and nearly 1,700 spent casings were found.
During trial, Bundy testified that the plan was to take ownership of the refuge by occupying it for a period of time and then turn it over to local officials to use as they saw fit.
Bundy also testified that the occupiers carried guns because they would have been arrested immediately otherwise and to protect themselves against possible government attack.
Quite. Just what I said. They would haveĀ been arrested immediately otherwise because they had broken into a closed (for the weekend) federal facility, so the guns were to enable them to commit the crime, and then to continue committing it for weeks.