A bit of an update on the "Target Tempest". A set and a half of Airgunner .177 grips arrived the other day. They are an unfinished Ambi set and a spare left with a thumb shelf for a right hander. I'll get round to doing a few finger grooves and then get the tru oil out.

I nicked the .177 barrel off my nieces Tempest to try on the pistol. Obviously the sights needed adjusting both for elevation and windage. ( I think the Webley forsights are not the best finished of items).
Once I'd adjusted the sights, I was getting some decent groups at 7 1/2 yards. The light was poor and I was shooting at a few circles drawn on an envelope. I think maybe the Hurricane rearsight blade is a fraction too narrow and does not give a great sight picture, especially in poor light. I'm not tempted to open it up a bit with a file.
The trigger feels good and very little recoil with the pistol. I think that maybe, the piston head could be made a mm or so longer and you will still have enough power in .177 for paper punching. I've noticed this gun is harder to cock than my nieces Tempest that just has a cut down Typhoon spring. That is more punchy and has a faster firing cycle and is more fun to plink with. I think the Tempest rearsight blade, which is a bit wide, actually gives a better sight picture than the Hurricane sight in most circumstances, but a slightly narrower cut out might be better.
So really it is down to taste and feel for sorting out one of these more seriously than I have done.
I think in .177, a 12 or maybe even 13mm long head might be the thing. I'm also thinking that a cut down Typhoon spring makes the gun easier to cock and just seems to feel better. Maybe a bit of work on a rearsight and some sort of adapter to screw into the end of the barrel ( using a Hurricane barrel) could give better sight pictures.
When the .22 barrel was replaced and the sights adjusted, the pistol shot very well.
For fun, I prefer the .22 standard stroke Tempest fitted with the Typhoon spring. I'm rather taken with the firing cycle of the .177 that has the standard stroke and cut down mainspring.
Anyway, that is about as much info as I can provide so it it up to the Wobbly boys to sort out one of their guns to the sort of specs that suits them best.