The only way of finding where your gun should shoot with no wind is to shoot it indoors, then you have to allow for the wind when shooting outdoors. Thats what shooting is all about, get it sorted so that it shoots where it should, and then your skill and experience tells you where it should strike allowing for conditions outdoors in a competition. Basically shooting indoors elminates environmental conditions that you will have to allow for later. Unfortunately outside conditions are not constant. Thats the problem that we all have.