both my hw100's my 97k and hw99s all are .177 and seem happiest with jsb exact 4.52,
my son has a hw99s in .22 and it works best with h&n ftt/weihrauch f and t
he has tried rws superfield and they group well but drop quickly it seems maybe its because they are heavier,typically with h&n's he gets a group around 18-20mm at 25yards rested
last weekend i did a session with the 97k and got groups of between 10-12mm with the exacts rested at 25yards
the hw100s do pretty much single cloverleaf holes at 25yards off a harris bipod
the hw99s does around 15mm c/c 25yards rested with jsb's,i'm fitting a v-mach kit to it and having a bit of a fettle with it so will see if it groups any better
my alecto prefers hobbies and accupels and my hw45 likes hobbies and h&n ftts
hw100t/mtc viper 4-16x50,,hw100k/nv scope,,hw97k/3-12x44sr6,,hw99s all .177
hw99s,,bsa supersport,,relum tornado lg15,,all .22
webley alecto,,hw45,,milbro cougar all .177