Here's an interesting remark:
My personal requirement is being able to engage a gallon milk jug first shot EVERYTIME as far as I want to hunt under the conditions presented. A smaller target would be chosen if hunting game smaller then a deer. In dead calm first light air, that might be 1,000yds.
Considering the very best long range competitors shooting a known load in known conditions at 1000 yards on a range the've got good zeros for, the percentage of the time their first shot strikes the 10-inch inner ring of the target is about 10% to 20%. That's about what a gallon milk jug represents.