What should be done with the barrel after pouring powder into it?

When you pour powder into a barrel, it's important to ensure that it settles correctly for safe and efficient ignition. Tapping the barrel gently helps to achieve this by promoting the powder to fall into the breech end, ensuring that the powder is properly seated and ready for the next steps in loading. This action minimizes the likelihood of inconsistent ignitions or poor performance, as it encourages even distribution.

Leaving the barrel upright for a few minutes or shaking it vigorously would likely not provide the same assurance of proper placement and could lead to an imbalance or potentially dangerous situations if the powder is not settled correctly. Ignoring the barrel until later can also lead to complications, as any residues or contaminants could affect the powder or the loading process. Thus, tapping the barrel is the most reliable method to ensure safe handling and performance of the firearm.