Mr. Brown,
I can't say that I patterned the shells at 70 yards. And, I well understand your point about the patterns.
But, as to the pacing, I am confident of it. I was a caddie at a country club for a few years in my teens. I practiced and learned to make a one yard pace. It was required and it was important. That was many years ago. But it was contemporary with pacing off shots on birds. To this day I can pace off out to a hundred yards within about 2 yards. This I have verified many times with a modern laser rangefinder or chains or known marks on courses.
I will well agree that 70 yards or so is the maximum end of shotgun range even with large shot. And, there is no doubt that there are plenty of holes in the pattern. But I am talking about shock and killing power at range in this discussion. And big heavy shot that starts off fast WILL kill at great range. Light shot and/or slow shot will not.
Jake