The huben and the sk19 work almost exactly the same, and have very similar parts. The sk barrel is easier to remove and install.
It shoots the redesigned jsb perfectly. Slugs have been a challenge for getting good accuracy. I've tried a lot of slugs and the best results with the NSA.
The sk19 barrel is super easy to clean, it's a lother walter choked rifled barrel (Not a polygon, not sure where that rumor started) It doesn't get dirty very fast. Taking the barrel off to clean it, putting it back together and adjusting it has some folks rattled.
The barrel is the main structural piece of the sk, and it only takes a 16th or so of a turn from bottom to be adjusted properly. A lot of folks mark the barrel to get it back to where it was, I didnt.
I dont recommend trying to adjust barrel in a working stand cause it binds the parts when tightening things back together.
I unlock the pellet cylinder, stand it vertically on its butt pad, tighten the barrel til it touches the cylinder, now trying to turn the pellet cylinder, I very slightly loosen the barrel as soon as the cylinder will rotate you're adjusted, I rotate the cylinder a full rotation to ensure not binds, I torque the barrel clamps TIGHT (if you dont the barrel will rotate at some point and will need to be readjusted)
To be honest the sk19 can suck if things are not adjusted properly. I almost sent it back to get a refund. AFTER I chilled out I learned a few things.
I've had jams that shear the pellet in half and lock up the cylinder, blows every once of air out if the gun and tank in a flash. Also had the barrel free but the cylinder would not rotate. Had where the skirts of the pellets get damaged when rotating in the cylinder (easy fix). All these problems happened in the first two days of owning the sk, since Ive take the gun apart numerous times for cleaning or modifying and zero issues.
If any sk19 owners run into these problems feel free to contact me... I've thought about making a write up or video on adjusting the sk and some tricks I've learned . Still might.
Once you learn things about it and know how to adjust it the gun is very enjoyable and doesnt give you problems.
The learning curve and lack of support other than AOA (which AOA has been great) is what give this gun a bad wrap. I think LCS should release how to videos and part diagrams to help folks out and would keep from people sending them back to be fixed.