Correct me if I am wrong but they do not seem like the groups shot from a 2000$+ gun. They are more like 200$ springer groups.
I want to add something to this. I've been shooting with a DonnyFL 14mm adapter and a Koi (.22) and Shogun (.25 - so less chance of clipping). Also a Hugget Astille .22. I tried all of these options out at 45 yards today and groups were still pretty big. So I decided to put the stock 350mm silencer back on and my groups tightened up out at 45 yards. Much closer to what we might expect from an airgun of this caliber.
I can't say if this was the 14mm
adapter which isn't a super snug fit to the barrel. Or, it could be the moderators are choking on the amount of air from the Leshiy 2.
I have a 14x1.25 adapter for the Koi and Shogun. I'm going to try some groups at 45 yards again to see if a direct attachment helps at all.