Pheroze, Stocky has an excellent suggestion. When I was hunting ground squirrels, prairie dogs, and such, (many rounds being fired all summer long) I had found my screws loose once in awhile (!) But when it was not in my head and actually pertained to whatever rifle that began producing unacceptable groups, I had my best luck tightening the screw just in front of the trigger guard very tight, and then the other one/s, depending on make and model. It is worth mentioning though, that my scope mount screws/scope ring screws were often loosening long before the stock screws vibrated loose from much firing. None of the above happened to me very often (and I have owned a pile of rifles) but it has happened and as Stocky suggested, check those screws, tighter groups might just be that easy. Likewise, in small bore rifles, bore fouling was usually the culprit more often than me or the rifle having our screws loose. But you are not bringing a small bore to Africa so, bore fouling, though still worth cleaning out for accuracy sake, is not quite as critical. Best Regards, Velo Dog.