I presume this figure is got with rapid fire. With single shots the gun would be more accurate. The firing rate of MK108 is pretty awesome for its caliber and since the weapon itself does not weight much the dispersion will rapidly build up shot by shot with 650 rpm.
In games the gun is modeled so that it is inherently inaccurate even with single shots so that even the first shot goes somewhere withing the dispersion cone and not near the center.
-C+