It was then customary for the friends and relatives of the deceased to repeat the word 'vale' (meaning farewell or goodbye) three times.
In more recent history three volleys were fired to signify the end of a funeral and that the burial detail was to be ready for battle.
However, if mourners are present near the grave, the party stands some distance away (often recommended at least 50 feet) so as to not deafen the attendees and to minimize the disturbance.
The use of blank cartridges means these weapon's semi-automatic gas action will not function, requiring manual cycling of the next round between shots.
Similarly, the M1 and M14 are generally preferred over the current issue M16 because the appearance of these older rifles is more traditional and the charging handles are more easily operated in a dignified, ceremonial manner.