In one embodiment, an automatic injector comprises a cartridge adapted to contain a charge of medicament, a seal structure disposed toward a forward end of the cartridge, a plunger normally disposed in a generally rearward end of the cartridge and movable through the cartridge toward a generally forward end thereof in response to an actuating procedure. The movable plunger rearwardly confines the medicament within the cartridge. A needle normally disposed in communication with the medicament container provides a passage in which the medicament is released into an individual's flesh in response to an actuating procedure projecting the needle into the flesh of the individual. The cartridge having an increased friction region so as to slow the motion of the plunger when the forward end of the needle travels through the seal in order to eliminate coring.