public boolean prime()
    {
        boolean didPrime = false;

        if (_shots > 0 && _ammo == null)
        {
            didPrime = true;
            _ammo = new Gumball(_ammoImage, getPosX(), getPosY(), 0, 0,
                    GameSettings.GUMBALL_MASS);
            _shots--;
        }
        return didPrime;
    }