@Mania If you see you are missing very often skills or effects (both from dino or weapon) then you need to use focus tech, this happend mostly with hammer, colt, gatt. Yaeger at level 55 doesn't miss on hunting but i don't know if in some cases like war it can get misses. Peacemaker at level 55 doesn't have miss, and showstopper i think it doesn't have miss even on since low levels like 45.
On sumary if the miss are anoying you using gatt, hammer and colt then is better you use focus tech. However focus tech doesn't counter the hitchancedown, it is only countered by hammer's hitchanceup (it goes on the caster so it never fails) or by pachy's easytarget (it goes on the target so it can fail)