WRITTEN STEPS!!

1.go into the console (~)
2.type in "sv_cheats 1" (without the commas)
3.buy the glock
4.go to semi auto mode and then at the same time press g and right click (THIS HAS TO BE PERFECT!!), if you did it right, then you should be firing full auto and with unlimited ammo
Things to remember:
does not work in multiplayer, only the fist shot will be an actual shot that does damage (less info)