Right!
Okay... new seals arrived as promised. For anyone else with a Model 46 who hasn't yet noticed, the seals aren't a great fit to the breech; they compress relatively well when thumbed in, but when the breech is opened they start to rise up. If you don't keep an eye on them they'll either fall out or prevent the breech *clicking* shut and fly out at you! (5th shot through chrono).
We sorted the problem with a fine layer of contact adhesive applied to the edge of the seal and *touch wood* so far so good. I gather Diana will be updating the 46 to have the sliding breech as on the 48/52 which will solve the problem.

So, nice bright sunny Saturday afternoon, just the ticket to pop some targets up in the garden and see what happens!
I'd tried using Chairgun to get some rough data; it is rough as the minimum scope mag is x2 on that, but at least I could get an idea of the trajectory. From 8-20 yards is near enough dead on, with every 5 yards after that accounting for about an inch drop.
With a paper target at 15yards I was getting fairly comfortable 15mm groups, so with a heightened sense of optimism I put out some of Dads home-made knock down targets with 20mm killzones.
With a 'proper' target to aim at things now got interesting. First off, what to do with your left eye. I found I had to close it as keeping it open (as you can do with a telescopic sight), simply meant multiple foresight images and a blurry mess. Closing it is fine, its when you keep doing so that it starts to get a bit grumpy and refuse to focus on anything when you open it again. For one shot at a time it shouldn't be a problem, but doing groups of 5 and 10 shots into a target meant I nearly fell into the pond when I tried to see again.

Second thing to note is that the sights become bigger as the target gets smaller, and at this point you start questioning exactly where they should sit together; rear blade dead level? Up a bit? Down a bit? And where on the target? Right on it or just above or below? Moving your head a tiny amount can alter it drastically.

I managed to hit the 20mm kill zone out to 25 yards with a not surprisingly increasing number of plates! At 10yards I could hit it about 50% of the time, by the time I got out to 25 yards I managed it twice in 10 shots. I didn't hit the blighter once at 30 yards and must have lumped the best part of 50 pellets at it. -I stopped when I'd decimated all the paint and could no longer see where the shots were grouping! At this point I thought I'd pop a paper target up (the standard 10M type with 5 bulls on) and fire a group of 5 shots from 30 yards to see where they fell. As expected the grouping was quite large and the average 'fall' from aiming at a top bull was about 2 1/2". From the 5 shots I managed two within the black area of the target below.

30 yards is about the max range I have here, so I'll take a pen and pencil with me tomorrow and do some quick notes after some time on the plinking range at the 35-45yd targets.
Just to make things really interesting... I have no idea how the rifle behaves with different holds when lying prone. The garden is still quite damp from all the rain we've had so all shots so far have been taken as unsupported standers. Still, should give the other shooters something else to gawp at tomorrow!