Apparatuses for automatic medicament injection and methods for manufacturing automatic medicament injectors are described herein. In some embodiments, an apparatus includes a housing, a needle, an energy storage member, an actuator, a locking member, and a needle guard. The needle is configured to move between a first position and a second position. In its first position, the needle is contained within the housing. In its second position, at least a portion of the needle extends from the housing. The energy storage member has a first configuration and a second configuration and is configured to produce a force when moving between its first configuration and its second configuration to move the needle from its first position to its second position. The actuator is configured to move the energy storage member from its first configuration to its second configuration. The locking member is movably coupled to the distal end portion of the housing such that the locking member can be moved between a first position and a second position. In its first position, the locking member is configured to engage the actuator to prevent the actuator from moving the energy storage member to the second configuration. The needle guard is removably coupled to at least one of the distal end portion of the housing or a base movably coupled to the distal end portion of the housing.