I tried every pellet known to Man after I retired, washed lubed waxed drawn and quartered and found to my surprise that it made little or no difference at all!
bit sad really,
On regaining my senses I had it figured,

Good quality pellets make all the difference, you get what you pay for,

There are three main contenders, JSB, Air Arms (both made in the same factory) and H&N,

All three will make most guns happy, but one of them will perform the best in your gun (pellet to barrel)

Clean your barrel, fire 30 pellets, then a test group on paper, having found the best performer use that,

if you really want perfection weigh your chosen pellets and buy a sizer to make them totally consistent,

Happy And Safe Shooting.