That is a beautiful rifle you have there. No doubt about it. Is one shot a group? No even by definition. "An assemblage of persons or objects gathered or located together." Note it does not refer to a person or object but rather these items in a plural sense, meaning more then one.

I have to agree with chetmarks. I would have shot at least two more, simply to check the validity of the scope, and the load as well. Not to mention the shooters skill. Yesterday while shooting my White I shot two separate bulls eyes with one shot each. While I did this to test the rifle and my self, I could not consider them groups.

Those disc rifles are simply good shooters. I am sure that your one shot could and probably did turn into multiple shots forming a wonderful group. Besides if you don't shoot more them one, how on earth are you going to get a flier to cuss and moan about?