I wrote this off the top of my head, it should work, give it a try, it'll shoot 10 bullets repeatedly.
sync on
sync rate 70
rem make character
make object cylinder 11
0=x#
0=y#
0=z#
position object 11,x#,y#,z#
rem make and hide bullets
for x=1 to 10
make object sphere x,10
hide object x
wait#=0
showbullet#=1
do
if mouseclick()=1 and wait#=0
show objcet showbullet#
position object showbullet#,x#,y#,z#
inc showbullet#
if showbullet#=11 then showbullet#=1
wait#=20
endif
dec wait#
for x=1 to 10
if object visible x
move object x,2
if object collision(x,0)>0 then hide object x
endif
next x
sync
loop
am I missing anything? That should work.