Some of your ranged weapons in Warhammer 40k: Rogue Trader come equipped with multiple distinct rates of fire that you can use depending on the circumstances
Keep in mind a few things when doing so though:
- If you use burst fire instead of single shots, your likelihood of hitting will be penalized more. With each subsequent shot, recoil will lower the ballistic skill role by the weapon's recoil value, which can be a quite large drop.
- The bonuses that you would have received for hitting with a single shot will also not be given to you.
- Burst fire will shoot a number of times up to a maximum of the weapon's rate of fire.
Keep in mind that these kinds of attacks will have an element of spray and prey to them.
Shots will deviate from the central target, which may result in friendly fire or deal heavy damage to several adversaries at once. To deal the most damage possible, make sure your attacker is positioned correctly.
Lastly, remember that you must reload in order to fire a ranged weapon because they have ammo. You may find yourself reloading more frequently than necessary if you use burst fire frequently because it will deplete a clip faster and with less overall accuracy.
In my opinion, burst fire may be a very useful tool, particularly when it comes from a bolter of any size or type.