Charlie,
I have not been shooting heavy or light pellets, 7.9 to 8.4. When I got the tube cleaned out and looked down in it, it looked burnt near the port. I've cleaned the tube and chamber with denatured alcohol, ordered a new 33 coil tarantula spring, small apex seal and gamo .995 seal. May need some coaching on putting the moly paste on and how much.
Thanks
Jeff