Code:
bind e "weapon 1;_lgOff" //GT
bind r "weapon 2;_lgOn" //MG
bind mwheeldown "weapon 3;_lgOff" //SG
bind mwheelup "weapon 4;_lgOff" //GL
bind space "weapon 5;_lgOff" //RL
bind shift "weapon 6;_lgOn" //LG
bind ctrl "weapon 7;_lgOff" //RG
bind f "weapon 8;_lgOff" //PG
bind x "weapon 9;_lgOff" //BFG
//LGMG sens tweak
alias +fire "+attack"
alias -fire "-attack;_normsens"
alias _lgOn "alias +fire _lgfire"
alias _lgFire "+attack;_LGsens"
alias _lgOff "alias +fire +attack;_normsens"
alias _LGsens "sensitivity 0.58"
alias _normsens "sensitivity 0.65"
_normsens
It will do just as you like for LG & MG. Sensivity when firing is alias _LGsens "sensitivity x". If you don't want that tweak for MG, just make "weapon 2;_lgOff"
That will do.