Tim takes the Brown Bess, a rifle, from his brother Sam to protect his father against the continental soldiers. At the beginning of the chapter, Sam runs toward his house when he sees the soldiers approach. Out of sight, he sees them twisting his father's arm behind his back, demanding that he give them all of his weapons. When Sam's father tells them he doesn't have any, a soldier tells him "I don't believe you" and slashes his cheek with his knife.

Sam runs to Tom Warrup's house, who he says is the "one person who knew what happened to Father's Brown Bess." To his surprise, however, the only person he sees inside Tom's house is his brother Sam, sound asleep holding the Brown Bess tightly to him. Not wanting to wake him "knowing how tired he must be," Tim tries to delicately wrestle the gun from Sam's grasp. Sam wakes to Tim pointing the gun at his stomach. Tim tells him

Jesus, Sam, Jesus, they're down there and they're going to kill father if he doesn't give them the Brown Bess.

Tim's reason for taking the brown bess from Sam is two-fold.  First, he takes the gun in the hopes of preventing Sam from joining the militia (having a weapon was a requirement for joining).  He wants to prevent Sam from being in harm's way and to force Sam to come back home and stop arguing with their father.  Second, Tim knows that the brown bess is necessary for his family's survival.  Mr. Meeker needs it for both protection and to obtain food.  Without the brown bess the rest of the Meeker family will suffer.