Hello and welcome! All my hatsans in different caliber prefer heavy jsb pellets, so i would think those 18.13 jsb you bought would be god, clean the barrel first cause they are usualy filthy, don´t worry if the shotgroups get wide after cleaning, that happens all the time for me, it gets better after a number of shots when the barrel get seasoned, then shoot a couple hundred shots to break it in, god luck with your shooting!
My Hatsan 95s love RWS Superdome, both in terms of accuracy and FPE.-W
I'm new to airguns and optics, so putting a few hundred rounds over iron sights before bolting on a scope kept things simple for me