As far as I know, there isn’t one for the general public. I think but not sure that Huben is Suing LCS Air Arms over patent infringement on their design. That may have something to do with it but again I’m not sure. Air guns of Arizona I would imagine have a diagram of the gun since they work on them. I would advise not taking the gun apart other than cleaning the barrel really. A 3 year warranty on a 2100$ air gun that has a complicated design like the SK-19 is something I would recommend voiding. My actuator hung up around 5000 rounds and would not move due to lack of internal lubrication , sent it out and got it back 2 weeks later. Better to be safe than sorry. Hopefully in time we will have access to a schematic.