A medicament injection device arranged to receive a replaceable container subassembly having a medicament container with a plunger therein, a needle and a needle shield, wherein said medicament injection device has a proximal end and a distal end and wherein said medicament injection device comprises: - a front housing and a rear housing releasably connectable to each other, - a reloadable drive mechanism accommodated in said rear housing for acting on the replaceable container subassembly, said reloadable drive mechanism being moveable between a cocked and an extended position; - a release mechanism for releasing the drive mechanism from said cocked position to said extended position; - a needle hider front slidably arranged within the front housing; and - a needle shield remover arranged to connect with the needle shield of the replaceable container subassembly received in the reloadable medicament injection device, wherein said needle shield remover is arranged to be removably inserted into a proximal end of the front housing through the needle hider front; - the needle shield remover, when inserted into the front housing is adapted to be used to interact with the reloadable drive mechanism accommodated in said rear housing such that a user can re-locate the reloadable drive mechanism from said extended position to said cocked position; - a needle hider body is arranged within the front housing and wherein the needle hider front is adjustably connected to the needle hider body by means of a threaded connection, and wherein the front housing and/or the needle hider body is not provided with means defining a number of pre-set positions which snap in place when the needle hider front is turned; - wherein the needle shield remover and the needle hider front are arranged to mate with each other such that axial movement of the needle shield remover relative to the needle hider front is allowed while rotation of the needle shield remover relative to the needle hider front is prevented; - wherein the needle hider body is axially moveable within the front housing between a proximal end position and a distal end position and wherein a syringe guide is arranged within said needle hider body for receiving a replaceable container subassembly, said syringe guide being axially moveable between a proximal end position and a distal end position relative to the front housing and - wherein a proximal end surface of the syringe guide defines a maximum insertion depth for the needle shield remover; characterized in that the front housing comprises internal abutment surfaces defining said proximal end positions and distal end positions for the needle hider body and the syringe guide relative to the front housing. - a front housing and a rear housing releasably connectable to each other, - a reloadable drive mechanism accommodated in said rear housing for acting on the replaceable container subassembly, said reloadable drive mechanism being moveable between a cocked and an extended position; - a release mechanism for releasing the drive mechanism from said cocked position to said extended position; - a needle hider front slidably arranged within the front housing; and - a needle shield remover arranged to connect with the needle shield of the replaceable container subassembly received in the reloadable medicament injection device, wherein said needle shield remover is arranged to be removably inserted into a proximal end of the front housing through the needle hider front; - the needle shield remover, when inserted into the front housing is adapted to be used to interact with the reloadable drive mechanism accommodated in said rear housing such that a user can re-locate the reloadable drive mechanism from said extended position to said cocked position; - a needle hider body is arranged within the front housing and wherein the needle hider front is adjustably connected to the needle hider body by means of a threaded connection, and wherein the front housing and/or the needle hider body is not provided with means defining a number of pre-set positions which snap in place when the needle hider front is turned; - wherein the needle shield remover and the needle hider front are arranged to mate with each other such that axial movement of the needle shield remover relative to the needle hider front is allowed while rotation of the needle shield remover relative to the needle hider front is prevented; - wherein the needle hider body is axially moveable within the front housing between a proximal end position and a distal end position and wherein a syringe guide is arranged within said needle hider body for receiving a replaceable container subassembly, said syringe guide being axially moveable between a proximal end position and a distal end position relative to the front housing and - wherein a proximal end surface of the syringe guide defines a maximum insertion depth for the needle shield remover;