Since the available .577/480" ammo didn't fit in the available Martini-Henry rifle when making the Great British Rates of Fire Disaster Video here: https://www.youtube.com/watch?v=Y3YiJDgddWk

... a friend of the channel who goes by the name of Stan_Da_Bout on the Army Rumour Service offered to shoot 10 rounds through his, and who were we to refuse? So we let him. And topped it off with a discussion around the initial skepticism surrounding magazine rifles at the end of the Martini-Henry era. Luckily clearer heads prevailed, and the Lee-Metford succeeded it.