There’s nothing distinctive about these 3 groups which describes them as statistically different. Shot again, these groups might represent any of the 3 loads, with no reason to think any of them are actually different than the other.

Assign 1 & 2 to one load, 3 & 4 to the second, and 5 & 6 to the third load, roll a die, let it pick which one you shoot. It’ll be just as meaningful as choosing among these 3 targets.