The Bren is a slow firing, high damage LMG. At medium range it can kill in 2 shots. However, the slow fire rate means that you have no chance unless you are prepared for enemies and behind cover. Find a good spot where you expect to see enemies, set up the bipod and wait for enemies to arrive. The best attachments for the Bren are those that help you whilst you are holding down a position. Use the grip attachment to reduce the Bren’s recoil, which helps especially if you aren’t currenlty using the bipod. Use full metal jacket to increase the penetration of the Bren which helps when you are fighting enemies behind cover.
The best division for the Bren is armored as it grants protection from enemy lethal and tactical equipment and gives you the bipod. The best basic training is lookout, which highlights enemies from further away, as you will want to be pretty far away from enemies and they can be hard to see at that distance. Pick your favorite secondary for when you have to move through close quarters or use the mk 2 fragmentation grenade to clear out close quarters before going through them. Here is the complete best class setup for the Bren..
As found on Youtube