Cam - re. the 'reg'. I think you're absolutely right about what constitutes a 'proper' reg... and I'm kind of with Jamesy and you on this one that it's a metering system of sorts. As Jamesy quite correctly points out, it is a little unfair to compare it with a simple knock-open valve, because the HW system is so much more consistent... although I also think it a little unfair to compare the HW system with that of, for instance, the EV2 and Dave Welham's units. They are
regulators (IMHO), but I'm not sure I'd want to dub the HW's design as such! Why don't we say that the HW100/1 isn't regulated, but uses an air metering design that is as effective as a conventional regulator? (A bit like I always refer to the Daystate Air Wolf's action as a 'kind of digital air regulator'.)
And, of course, how could I print in my article that the HW101 is
regulated... when Hull clearly told me it wasn't!
On the subject of the breech movement, Cam, I confess I've not experienced this myself... but then I've never owned one of these models, so only have limited experience to draw on; typically, I'll be using a test rifle over a period of two or three months - and as it's not my own rifle, I don't get to know it to the 'nth' degree like I would my own. That said, I do know someone - a big HW100 fan, actually - who has owned lots of them and has pointed a suspicious finger toward this area on a couple of them. When you consider the two-part-breech design, it's certainly a plausible explanation - and while a one-piece mount may be the answer, I wouldn't like to rely on it being the belt and braces of my rifle's accuracy!
Next time I talk to Hans, I'll mention this. It could be one of those 'potential' problems (by way of design) like the HW35 has, viz if the solder doesn't flow all the way around the breech plug (the jaws/transfer port), you end up with a rifle that's uncharacteristically low-powered because of the air leakage into the empty solder channels.
As you probably know, Mssrs Weihrauch are very set in their ways (!), but I think an adjustable cheek-piece is something they'd certainly consider on an HW100/1. Like everything, it all comes down to cost, and they are very conscious that the UK market is very price-point conscious, particularly at the moment. They usually try a 'limited run' to see how things go. Mind you, the success of the (cheaper) HW97K-T Synthetic certainly bodes well for us seeing a synthetically-stocked PCP from them in the not-too-distant future... but I didn't tell you that.