A very interesting post. It is pleasing to read about high quality rifles other than HW and, in my (humble) opinion, Diana's Original 45 was one of the best air rifles ever made; it is unfortunate they did not upgrade and keep the model going. I rather became lost when they introduced so many alternatives, such as their range with thirty something or other - poor marketing in my view. Everyone had heard of the 45.

There is presumably quite a curvature in the pellet flight on a .25 calibre. If sighted at 30 yds, there must surely be an enormous hold-under and hold-over at 20 yds and 40 yds.