Strikey wrote:There may be oil or grease from the spring in the compression chamber causing dieseling, if it continues or gets worse you may have to strip it down for a good clean.
Dieseling for sure.
One drop of mineral oil into the cylinder will have the rifle dieseling for a long time and it will almost certainly show indifferent accuracy.
Would probably be a good idea to strip and clean, some knowledgeable folk reckon a little silicone oil to be the go.
I once damaged a Diana 52 with one drop of mineral oil, dieseling flame cut the plastic breech seal and piston slamming then broke the spring.
If you pull it apart PM me and I will send you some Jim Macarri spring tar [google it], reduces spring vibration and increases accuracy, if you want it to shoot really well order a spring kit from Macarri ex USA.