Tuning Benjamin Kratos .25 Eating o-rings

[Chris-Kratos.25]

I finally found the correct orings. I’ve been shooting JSB 25 GR pellets out of it (60 or so) so far so good. I think it had something to do with the EBay barrel band I have on it. Maybe it was putting pressure on the back Oring by not keeping the barrel true

 

[KatoKevin454]

I think it's the Barrel mounting block, sharp edges on the barrel block opening or the mounting screw holes have burrs, my Hatsan's had very sharp edges on the barrel block opening, had to chamfer the opening to keep it from chewing up the barrel O-rings, just about exactly the same as your gun.