five No restrict 12 12 Ball Pasters B1 and B2 12 single rd (zero). 10) The gunner engages paster B1 with a few single pictures when he is ready. 4) The assistant gunner relays the Ready sign to the tower operator. 1) The tower operator instructs the gunner to prepare a 56-spherical belt (M249) or 72-round belt (M60/M240B). 1) The tower operator instructs the gunner to prepare a 56-round belt (M249) or 63-spherical belt (M60/M240B).