I posted a solution for this kind of thing on another thread, but heres a suggestion:
Use an invisible target addon (BAS Tonali Pack and MMP have them) and a simple script to place them around the tank. Combine with a reveal and dofire command and you should get the desired result. The example script would also need the DirToObj.sqf function which can be found in the ed depot function page.
Untested example script:
_it=invistargname
_tank=nameoftank
_targ=nameoftarget
;distance from target you want round to impact
_missdist=25
;keep tank from firing at target prematurely
_tank setcombatmode "green"
;--------------------------place invis target-------------------
_dir=[_targ,_tank] call dirtoobj
;randomize placement left/right of axis of fire
_rdir=_dir+random(180)-90
_pos=getpos _tank
_xp=_pos select 0
_yp=_pos select 1
_nxp=_xp+(_missdist*(cos _dir))
_nyp=_yp+(_missdist*(sin _dir))
it setpos [_nxp,_nyp]
;--------------------------fire at targ cycle-------------------
;number of rounds to fire but miss
_rnds=10
#firetop
_rnds=_rnds-1
_tank reveal _it
_tank dotarget _it
_tank setcombatmode "red"
_tank dofire _it
@unit ready _tank
_tank setcombatmode "green"
;wait to reload/"retarget"
~random(5)+5
?(_rnds>0):goto "firetop"
;back to normal
_tank setcombatmode "red"
exit
This will take a little work to set up (i.e. downloading addon/function and seting up function in init.sqs) but it should work (...should). I'll test tonight.
-Grendel
BTW, actually the bit about using camcreated shells along with seeing/hearing the tanks fire would be easy as well, it would just need more code for some drop/sound efects. I can do a script for this as well if anyone is interested (or the invis target thing doesn't work as planned). Does that mean I should go on the official forum and let BIS know I'm ready to teach LOL