Standard rifle carry

[thomas aagaard]

when one came off sentry duty how did they get the ball and powder out of the barrel I imagine it would not always be possible to unload it but firing it

Undisciplined soldier did fire them out early in the war. Resulting in alarm... and then later the lack of alarm at the sound of firing.
Both problematic.

So as mentioned above, there is a tool to pull it.

 

[7thWisconsin]

I think firing it clear was the civilian way. Hence the poetic "knew the sound of father's gun when he was coming home." It must take a bit of discipline and command to get those guys to use a puller instead.