This sort of thing appears with some regularity on the forums, product reviews, etc., so I can only assume there is a significant number of people who don’t quite understand how a shot group on a target is measured. What I recently read on an ammo review is that, since the bullet is x diameter, your group size cannot be less than x.
That’s not how it works. (Boomershooters bear with me, I’m pretty sure you all know this) For the size of your group on the target, you’re measuring the center-to-center distance between hits. If your holes were clean enough to allow such precise measurements, it is in theory possible to have half-inch diameter bullets and a group size of a hundredth of an inch or less. You could just as well, theoretically, have an eighteen inch Navy ship’s gun that shoots a group of 1″ (all rounds through the same hole, to within one inch of center). Actually getting a gun and several projectiles to do that is of course another matter, but it wouldn’t violate the simple theory of taking a distance measurement on your target.
This isn’t rocket science. Well, maybe some aspects of shooting are in fact rocket science, but measuring the distance between centers of a few holes isn’t complicated, and has nothing to do with the diameter of the holes. Any carpenter, machinist or cabinet maker, etc. knows this, and it is often learned by farm mechanics in early childhood.