onClipEvent(enterFrame){
if(this.hitTest(_root.gun) && _root.gun._currentframe>1)){
this.play();
}
}

Providing your sniper scope clip is called ‘gun’ you should have no problem!

1. you neither need the onMouseUp nor the onEnterFrame at _root. You can do it simply by an onMouseDown
2. don’t use Mouse.hide() in an enterframe – it is enough to hide the mouse once (clipevent on aim)
3. if the vars acceleration and drag are the same use only one
4. in the code you call the play-method for a non-existing gun mc
5. put every script in a single frame (no need for object scripts any more)

something like that will do (frame script at _root):

//——————– vars ————————-
var nAmmo:Number = 12;
var nCash:Number = 100;
var nDrag:Number = 0.05;
//——————– functions ————————-
function initGame() {
this.onMouseDown = shooting;
aim.onEnterFrame = moving;
Mouse.hide();
}
function moving() {
this._x += (_xmouse-this._x)*nDrag;
this._y += (_ymouse-this._y)*nDrag;
}
function shooting() {
aim.play();
}
//——————– start ————————-
initGame();

http://www.mediafire.com/