Why has dieseling suddenly started?

[dayglowfroggy]

Owned a webley exorcet for just under a year tuned by previous owner and shoots fantastic also trigger is set perfectly never even considered pulling it apart.
Acuracy in my garden was weihrach level.

Can't say i have used it allot maybe 3 or 4 hundred shots in the last 11 months, it had its last big week long outing over Christmas when i fitted a peep sight.

Anyway got it out and put a new to me airmax scope on it.

Felt like i was chasing zero settled down a bit then off again i did notice a little smell.

Checked all the mounts and screws then had another go on the daylight today same problem but allot of diesling.
Not consistent maybe two bad one ok one bad one ok etc.

My thoughts are it's kept in a cold place normally but this last week i two weeks i have stored it up very high inside the kitchen on a shelf in a heated house.

Could i have damaged the piston seal shooting it in extreme cold?

Could the central heating have loosened up what ever grease is inside it?

Its never felt warm and it shot fine on summer days.

I didnt exactly ask its life history from the previous owner but its in very good condition and looks barely used.

Forgot to say removed scope and put that on my 97 works perfectly.