After firing a gun, the casing of a round may get stuck on the ejection port of the exit chamber. This causes the firearm to be unable to load a new round until the casing is removed from the ejection port. A common reason for a casing to get stuck is a weak grip on the firearm.
In some cases, you may pull the trigger and nothing happens (no bullet is ejected). If you pull the trigger and nothing happens at all, the issue is referred to as a misfire. If there is a delay before the discharge of the round, this is referred to as a hangfire.
In order to adhere to safety in the case of a hangfire or misfire, remain in the shooting stance for at least 30 seconds to make sure that you don’t cause any harm from a delayed action. You can later remove the round and examine it for any indentations that may cause it to get stuck.