An injection device including: a body including a syringe locator for receiving a syringe; and a firing mechanism including a rear cap, a plunger configured to be axially displaced in a forward direction relative to the rear cap and a driver system for driving the plunger forwards upon activation of the injection device, the firing mechanism configured to be directly or indirectly connected to the body such that an axial spacing of the rear cap and a barrel of the syringe is fixed during operation of the injection device, wherein, the firing mechanism and/or the body include first and second connection features allowing adjustment of a relative axial position of the firing mechanism and the syringe locator during assembly of the injection device.