scuba52, I'll try to explain the problem one last time.
Yes, groups will expand as distance increases. When measured by MOA, groups will always get larger as distance increases. With .22LR it will be at a ratio that's greater than it will be for most centerfire ammo -- that is .22LR groups will expand more quickly than CF groups. And certainly no rimfire ammo does better (MOA-wise) further out than it does at shorter range.
At 100 yards .22LR ammo will reveal how well it shoots. In fact, serious BR shooters distinguish between nearly identical good lots at 50 yards. The key is to shoot enough groups to get reliable information. The same applies to longer distance shooting. Shooting only a few groups isn't statistically reliable enough to draw conclusions. This is the weakness with the examples given in post #79 where three groups were shot with each ammo at three different distances. If more groups were shot at each distance the results would be very different. Three groups shot with each ammo is not enough to draw conclusions because there's too much left to chance, random acts of either inaccuracy or accuracy.
As far as some ammos not increasing in group size as fast as others as distance increases, there is no physical force that would explain how that would happen. When the bullets get to the 100 yard point, there's no internal mechanism telling them to discontinue the trajectory that got them there and to do something different such as tightening up so as to diverge from one another more slowly. The bullets continue on the course that took them to 100 yards and beyond. They are what they are at 100 yards based on the path that took them there and continue their journey on that basis. Forces such as wind only serve to make that journey more inaccurate as it continues.
As much as shooters may wish to have a .22LR ammo whose accuracy doesn't deteriorate as fast as others, it doesn't exist. All .22LR ammo bullets can only obey the rules that got them to a certain point and they must continue obeying them further on. The rules don't change between one make of ammo and another.