This Script fires a three round burst when enabled. This is good for weapons that don't have a secondary fire.
Script Code:
alias burstfire "bind mouse1 burst3; bind end standard; developer 1; echo Burst Fire Enabled; developer 0"
alias burst3 "+attack; w3; -attack; w3; +attack; w3; -attack; w3; +attack; w3; -attack"
alias standard "bind mouse1 +attack; bind end burstfire; developer 1; echo Burst Fire Disabled; developer 0"
alias w3 "wait; wait; wait"
bind "end" "burstfire"