Auto-injection device

A method comprising:

• axially inserting a syringe into a syringe carrier via a distal open end of the syringe carrier,
• the syringe comprising a barrel, a neck extending proximally from the barrel, a needle extending proximally from the neck, and a rigid needle shield covering the needle, and
• the syringe carrier comprising an elongate body having a slot extending distally from a proximal end of the elongate body to form a c-shaped proximal end region and a plurality of projections extending radially inward from the c-shaped proximal end region;
• axially advancing the syringe within the syringe carrier such that the rigid needle shield slides along the plurality of projections of the c-shaped proximal end region of the syringe carrier, causing the c-shaped proximal end region of the syringe carrier to flex radially outward;
• and
• further axially advancing the syringe within the syringe carrier until a distal end of the rigid needle shield is proximal to the plurality of projections, allowing the c-shaped proximal end region of the syringe carrier to rebound radially inward such that the plurality of projections are disposed in a gap formed between the rigid needle shield and the barrel of the syringe.