Some1 found it n reply to me on another forum.
Here's what it look like:
1-create an empty M1A1 Abrams, name it "tank1"
2-create a barel and name it "barel1"
3-create a soldier, name it "sol1" and on its Init box type:
sol1 moveingunner tank1; sol1 dowatch barel1; sol1 dotarget barel1;
4-create a trigger, Activation: West, present
condition: this
onActiv.:sol1 setpos(getpos barel1);[[sol1]] exec "del.sqs";
create the script an name it 'del.sqs'
_v0 = _this select 0
_t=0
_n=count _v0
#loop
~0.01
_ck=_v0 select _t
deletevehicle _ck
_t=_t+1
? _t>_n:exit
goto "loop"
That should be it, it take a certain time (3-4 seconds) before the canon rotate, but it's nice.
Thx to xaviernator