Yep, I use this:
not sure if putting it in autoexec will change the menu, but you can try. If not, change the Weapons menu in menus_settings.cfg.
[SELECT ALL] Code:
newmenu Weapons
menumdl weapons/assault/menu mapmodel 75 12
menuitem "MTP-57 Assault Rifle" "nextprimary 5;echo MTP-57 Assault Rifle selected;sensitivity 4.1" "chmenumdl Weapons weapons/assault/menu mapmodel 75 12"
menuitem "A-ARD/10 Submachine Gun" "nextprimary 3;echo A-ARD/10 Submachine Gun selected;sensitivity 4.1" "chmenumdl Weapons weapons/subgun/menu mapmodel 75 12"
menuitem "Precision Tech AD-81 Sniper Rifle" "nextprimary 4;echo Precision Tech AD-81 Sniper Rifle selected;sensitivity 2.8" "chmenumdl Weapons weapons/sniper/menu mapmodel 75 12"
menuitem "V-19 Combat Shotgun" "nextprimary 2;echo V-19 Combat Shotgun selected;sensitivity 2.8" "chmenumdl Weapons weapons/shotgun/menu mapmodel 75 12"
not sure if putting it in autoexec will change the menu, but you can try. If not, change the Weapons menu in menus_settings.cfg.