Morning @JackSofty,If you had paid attention to the movie, you would see that each soldier has a personal supply of rounds in the ammunition pouches of his 1871 pattern belt equipment. Even in a confined redoubt, it would not be feasible for the QMS and his staff to be feeding individual rounds to each man (you must have noticed that the Martini-Henry is a single shot weapon too).
You are making the common error that the cyclical rate of fire of a weapon is how many rounds can be put through it in a given time (an error that the twunk P. Morgan repeats often).
It would be stupid of any Rifleman or other soldier to just keep it squeezed until empty. He would very soon cease to exist, run up the curtain and join the choir invisible instead of pinin' for the fjiords and be unable to protect his squad, gun group, fire team or wotever.
Rate of fire is largely immaterial except in the case of support weapons (my role in my gun group, squad, patrol, fire team for much of the time) in which case the rest of the squad carries extra ammunition for that weapon's operator.
Just because an assault rifle may have a rate of fire of eg. 300 rds. per minute, there is NO WAY that anybody can put 300 rds. through it in 60 seconds.
Sent from my karzi while losing several pounds
My bold. Michael Palin walt.