I have a Daystate MK3 that, a couple of months ago, appeared to loose accuracy overnight. I was sitting at work the other day looking at my calander, My troubles started when I had a week off work. What did I do during that week....I bought half a sleeve of JSB's, checked they were ALL FROM THE SAME BATCH, weighed and sorted them....then it went down hill. I did everything I could think off, It was very consistent over a chrono so I Knew the reg was ok, I even paid £125.00 for a service (which it didn't neeed) and had the batteries replaced. I replaced the scope and bought a presilencer incase the MFC was clipping. I've not shot at the club for about 6 weeks because ...there was no real point, I had lost the will to live!!....until last wednesday night. I went to Pete's Airgun Farm and found an old tin of JSB's in the boot of the car......and guess what? NORMAL SERVICE RESUMED
Over the last few weeks I had tried many different makes of pellet and sizes but nothing came close to what it used to be. I just could not understand how the accuracy could go overnight.
Happy now though