Thank you, everyone, for your contributions which I found most interesting. It appears that there is no particular pattern at work, here. I expected, when I started the thread, to see a clear preference one way or the other but that seems not to exist.

I can quite understand that some collectors prefer 177 if few of these were made in the rifle in question - the FWB 124 being an example here.

Equally, the 177 has a lower trajectory, which gives it an advantage over longer ranges.

I did expect to see some preference for 22 in sporting use and also where rifles are used for both purposes and this has been touched upon but not to any predominant degree. Whilst, traditionally, 22 was used for sporting purposes and promoted by the manufacturers for this, I seem to recall a fashion for 177 in 1980 through, say, to 1990 and perhaps longer.

There is more of a skill in getting right the trajectory in 22 but this is much assisted with a telescope.

As for the .25, I have never had one of these as I was deterred by the curved trajectory.

Rgds to all
Andrew.