I guess you could try the giving something the timer-behaviour and do it like this:
create global variable "numberofbullets" and set it to 0
every 5 seconds
system set variable "numberofbullets" to 10
tart timer "bullet" for 0.1 seconds
on timer bullet
call function "shoot"
on function shoot -
spawn bullet
system subtract 1 from variable numberofbullets
- system compare variable "numberofbullets" > 0
> start timer "bullet for 0.1 seconds
But the loop thing is obviously much better.. haha