Nielsen Specialty Ammo week 2 winner!

Winner of week 2 here, I need some help. First I need to thank Nielsen Specialty Ammo, and Michael from AGN.
Currently shooting Impact M3 Compact .25 cal, 500mm bbl. Shoots like a lazer with JSB King Hvy MKll at around 790fps
Settings are:
1st reg 145
2nd 110
PW 16
Micro 3 1/4
Valve about 3 1/2
Was set up this way by Baker Airguns.
Looking for suggestions as to what grain slug to get that will shoot well without any setting changes. Thanks