I acquired a Walther .22 target rifle that closely resembles a KKM but only weighs a little over 8#. It appears to have an adjustable trigger but it is accessed from the left side of the stock just above the trigger guard, not through the trigger guard bow.. I can't find any information on adjusting this trigger and am asking that anyone who knows what the designation of this rifle is and who is familiar with this model to advise me as how to adjust the trigger. I cannot see down into the hole and can't even tell if an allen screw driver or a flat blade screwdriver is required.