Shotgun shells eject from gun?

Would anyone know how to add bullet effects to a gun. At times when i play a custom WAD i see that the shotgun ejects shells when you cock the gun again. i want to keep the original shotgun so i would just have to replace my edited shotgun with the original one. i also want to edit the ticks because i have a custom sound but the sound cuts off. could someone help? im using the skulltag engine.

Have you tried adding a Casing spawner to the shotguns fire state?

Um no. I never knew about that. So do I just add it and they spawn or what I'm really lost.

Well I looked at it. I downloaded the spawner from realm 667. I saw the demo map. Now I see that the casings were on the floor. Yeah I want that, but I need to know if I could make the bullets/shells spawn whenever I shoot a gun. Like if I shoot the shotgun I want it to cock and I see the bullet eject from the gun and then they go on the floor.

You would have to draw that into the sprites.

Oh okay that makes sense. Thank you