Further to my test with the BRNO 452 in the YOUNG MACHINE REST, I did this one for comparison.

All groups are 10 shots.

First target is at 50 yards, and the second is at 100 yards with the same ammo.

At the end there are only targets shot at 50 yards, as I ran out of those ammo at the time.

Wow, on that .662 group at 100 yards with the Lapua HP! The Aguila Super Extra at .807 was not shabby either.
It seems there is always something new to learn with .22 LR ammunition -- and there seems to be some weird magic involved, too.
Great report, Saeed.

I was surprised at how well the Lapua ammo shot but figured the Eley ammo would shoot better than it did. Thanks for doing this.