This is a simple marco using any programme such as razer synapse or corsair utility engine.
1. Open programme
2. New macro
3. Have the macro as "X" then "R" and set the delay time to 0.005 (you can test others i found this to be the best)
4. Bind macro to any key (would recomend somthing easy to press while moving in game)
5. Finnaly in game hold this macro down and hold shoot with any semi auto gun WORKS BEST WITH BRECCI
Also is very hit and miss, sometimes it works like a dream, sometimes it will do nothing - i have no idea the reason for this -
Macro has already been release by me :P By the way if you have a scroll lock so you can spin your mouse wheel extremely fast, you can spam R whilst the guns are spazzing out and then hold the shoot button.