The trigger mech and lower are specific to the Canadian rifles. As for a pencil eraser to tighten up the upper/lower wobble, there is a tried and true Swiss method of tightening them that completely eliminates any looseness. We have adjusted all the SAN rifles shooting at our Swiss Rifle club as well SG45X's. As for the comment by one poster that the looseness has no effect on actual accuracy, incorrect. I have witnessed on my rifles the before and after effect at 300 meters. I was taught this method by a former Swiss Military Armourer and fellow Swiss competitive shooter. Although small, there is most certianly an increase in "target grade" accuracy.