What is a sticker in artillery terms?

In artillery terminology, a sticker refers to a situation where a projectile lodges in the cannon tube after firing. This can occur due to various reasons, such as a malfunction or an issue with the round itself, and it poses a significant safety hazard. When a sticker occurs, the cannon cannot be fired again until the lodged round is safely removed, as firing the weapon with a projectile stuck in the tube can lead to potential catastrophic failure. Understanding this terminology is crucial for cannon crewmembers since addressing a sticker promptly is essential for maintaining operational safety and effectiveness in artillery operations.