Any select fire weapon, by definition, is capable of full-automatic fire. Autofire will normally be one of two rypes: burst or spray. Burst fire is a short, controlled group of rounds (typically 3). Burst fire can only be directed at a single target and improves the probability of a hit. Burst fire is typically utilized by auto and assault rifles and SMGs--light weapons not designed for sustained fire
Spray fire is sustained automatics weapons fire (typically 10 rounds per spray). Spray fire increases the probability of hit but also allows for group hits by automatic fire. That is, a weapon firing a 'spray' can potentially hit not only the target, but also other personnel in the immediate area. This 'spill-over' fire is resolved at a DM of -3. The referee my require a seperate roll for each additional target, or may simply allow for a random number of hits of spill-over should the shooter exceed his to hit by more than 3. Spray fire is normally only delivered by dedicated support weapons (LMG, VRG Gauss, etc.)
Sustained fire weapons may fire up to five (5) times per combat round, each firing consuming 10 rounds of ammunition. Each spray must be within a 45 degree arch. Each subsequent spray increases the chance of a weapon stoppage (jam). Roll 13+ to jam, with a +1 per additional burst. DMs are carried over to the next round. DMs are eliminated at a rate of 1 per tuns that the support weapon is not fired. To clear a jam, roll 10+ (+1 per level of heavy weapons skill).
Emplaced heavy weapons such as VRF gauss guns and heavy, water cooled machineguns may fire up to 10 sprays per turn. If more than 4 sprays are fired, roll 12+ for a minor stoppage, 15+ for a major stoppage. +1 DM per spray over 4, -1 per level of heavy weapons. A minor stoppage will put the weapon out of action for 2D6 - gunners expertise turns. A major stoppage will put the gun out of operation until major maintenance has been performed.
as usual, the Referee has the final say.