So, fishgod - did you get your Zelos .22? If so, how's it shooting for you?
Sorry for taking a while to get a proper update. I wanted to get any issues sorted before posting
I'm in Canada so I bought the Zelos .22 through Wes at Airgun Archery Fun, as well as a bottle adapter. Stand up guy, no problems there. The gun itself was flawless, however the bottle adapter was leaking at 2 out of 3 orings. The adapter to bottle connection oring was too small and unable to make a seal. (2.4mm thickness instead of the 3.1mm which I replaced it with). Also the fill valve oring had a large gash in it so I replaced it with a new identical one. Managed to get both at a local hydraulic store who didn't even bother to charge me for them since they were such small items.
After a thorough barrel cleaning, the gun is shooting excellent. As I want a fairly high shot count, I turned the pressure down to about 1600psi which had the JSB 18.13 (the most accurate pellet out of the ones I tried) shooting extremely accurately at 895-900fps.
Tuning it was a bit trickier as it seems the stock hammer spring was too stiff to have any usable adjustment at this lower pressure. Increasing spring turns was not giving any adjustment, in fact, it was slightly decreasing fps as the spring increased. I read about this on a different thread about the zelos and copied the shorter replacement spring suggested. This gave me adjustability from 500fps to well past the peak curve. I managed to tune it properly and the consistency of the fps increased, as well as the efficiency.
Shot count is excellent for me. After tuning, I get around 80 shots at full pressure, and the 700cc bottle I swap to afterwards gives me at least 200 more shots. So I am able to have close to 300 shots total at 900fps.
Accuracy is also excellent in my opinion. At 30 yards, a grouping of 5 shots makes one larger hole, about twice the size as the diameter of the pellets. I'd be pretty confident in being able to hit a literal pea or corn kernel 9/10 times at that distance. At 50 yards, they are less than 1/2 inch center to center. At 75 yards I get about 1 inch center to center. Anything beyond that distance and the wind played too much of a factor to give a fair rating.
Final thoughts: I'm extremely pleased with the gun once I got everything sorted out. The shot count is much better than I had hoped, so I may play around with increasing the pressure a little bit more. Accuracy has been great even in a light breeze, although I haven't had a dead calm day to try 100+ yard shots for fun. The trigger after adjustment is also very nice and light with in my opinion, a short and crisp second stage.
Happy to discuss anything else about it more, thanks again everyone for all the input!