hello there im shooing a FX impact mkii power plenum in .25 cal and trying to setup with 29gr NSA slugs im at 130reg and hammer maxed but min is 900 and max 995fps and none of them are accurate ive tryed 12345 and ABCDE but my groups are about 3" at 50yards any tips would be good or is it a case of they will never work in my gun . im using slug liner and lubing slugs with ballistol oil thanks steven