Takedown pins for rifles have a pin movable in a direction along its length between an operating condition and a released condition. The pin has a first end portion that prevents relative movement of the upper receiver with respect to the lower receiver when the pin is in the operating condition. The first end portion has a lower end portion surface adapted to resist upward movement of the upper receiver's lug. The pin has an intermediate portion adjacent to the lower end portion surface defining a lower channel having a lower channel surface above the level of the lower end portion surface. When the pin is in the released condition, the lower channel is registered with the lug, and the lug is enabled to move upward with respect to the lower receiver by a limited distance to a disengaged position.