Huben k1 jamming

Mine definitely does not seem to like many slugs. In some cases when testing I could only load ~5-10 before I felt significant resistance when trying to turn the magazine to load the next round. So I unloaded and didn't even try to shoot them with the mag so seemingly 'bound up.' For slug testing now. I only load 5 and shoot them out.

Never had any issues with pellets. At first I tried seating them but it seemed to have a bad impact on accuracy. So now I just push them in with my finger, turn the mag and repeat the process until full. Then I always turn my magazine at 10-15 clicks just to make sure it is moving freely before I lock it down and start shooting.

Have you turned the reg down? Kelly told me that the reg had to remain set pretty high to ensure semi-auto cycling.
 
Any time I've had problems it's been of my doing. I had a problem of occasional mag not cycling, started seating pellets and that took care of that problem. I was trying to discover the parameters, to low, didn't cycle, turned up the regulator and all is well. I've successfully shot my .177 at 10MPa, whata shot count. Even that low I can push 16.2gr JSBs supersonic. On my .25 the only issue is seating the pellets. I've not experimented on how low I can go.
 
Yeah, I had a great interest in the Huben K1 but found out that parts and support is not available in US. The trigger are smooth because it does not use hammer spring.

I'll pass

I’m not sure where you got this information but it is wrong.

As stated above by wimpanzee, KrazKool airguns will service them. I purchased mine from John at New England Airguns (newenglandairgun.com) and I’m sure he will service them as well.