An auto-injector is disclosed. The automatic injector comprises a housing having a retention step formed on an inner surface of the housing； a cartridge having an opening therein and containing a medicament, the medicament rearwardly confined by a plunger received through the opening, the cartridge including a needle assembly operative to dispense the medicament there through during a medicament dispensing operation, the needle assembly including a needle； a cartridge container disposed within the housing and operative to receive the cartridge therein, the cartridge container having a ledge that abuts the retention step of the housing to limit movement of the cartridge container within the housing during a medicament dispensing operation, the cartridge container having a closed front end except for an opening sized to receive the needle there through during a medicament dispensing operation, the closed front end operative to engage the cartridge and oppose continued movement of the cartridge after the needle passes through the front end opening； an actuation assembly providing a stored energy source capable of driving the plunger within the cartridge to dispense the medicament through the needle assembly, the actuation assembly secured to the housing； and a needle cover at least partially received within the housing and operative to receive therein at least the front end of the cartridge container, the needle cover extending beyond the housing and having an enclosed end surface operative to contact an injection site prior to a medicament dispensing operation, the end surface having an opening sized to receive the needle there through during a medicament dispensing operation； wherein residual force from the energy source after activation of the medicament dispensing operation is contained by the cartridge container, the cartridge, the housing, and the actuation assembly to prevent kickback of the automatic injector from the injection site during a medicament dispensi
