Well, unless you have some other events where CargaEscopeta is being reduced that will never work.
You have it set to 8 in the global variable and I do not see anywhere where you are reducing that number so your time event will never happen because it is looking for that variable to = 0
When i remove the events (timer,wait,etc) it works
(using the wheel to down you can change the gun)
The event sheet