Which jsb's will that be, am sure mine are 15.8grain
I am going to persevere tomorrow, see if I can get better results as its pissing me off.
Will get the cleaning gear out shortly.
If I can get it somewhere near I don't mind spending a bit on it to get the springer out of the pcp. Air fective seem to be able to do the business.
If it feels as good as you say it does mate then its worth putting that bit extra time and effort to get it shooting properly. I'll ask him which pellets they are Rob