12ga 2 3/4in Dummy Shells: Laffs Dynamics 3D printed dummy shell, dimensions of a 12ga (2 3/4in) cartridge. Printer Used: Ender 3 V2 Filament Used: PLA+ Print Settings: Extruder: 218C Bed: 56C First Layer Print Height: .18mm Standard Layer Height: .12mm - .16mm Wall Thickness: .40 Wall Perimeters: 5+ Infill: 32%+ Material Flow: 100% Depending on your machine's settings, you might need to scale +/- .01% for best fit of snap caps into the chamber. Accreditations: ProSpaceDog: Printed and tested multiple dummy shells. Shells tested in a Remington 1100 semiauto shotgun. Gave data on reinforcement structures within the shell. Provided still images.