I’ve used all the available .20 pellets in my Hw 100 and the best by far are jsb exacts. I don’t know of a 100 that doesn’t like exacts.
Interestingly I found .20 bisley super fields ( can’t remover exact weight) just as accurate at 50 yards and even more interesting they had exactly the same poi as the heavier 13.73gn exacts with no scope adjustments.
The exacts have a far superior BC so are much more efficient.