I use to buy pelletes online. I had a couple of bad tins. But the thing is Postnord in Sweden is taking heavy flak for throwing packages like baseballs. Called the Airgun shop (Hurricane luftvapen, great shop) and asked them to make some extra good packaging, and after that no problem. It is not fun...
It seems that every gun has it's personality. My AA S410 .22 has it's sweetspot between 160-105 bar. Don't need a regulator when you know that. Happy New year.