You need to read this...
https://www.fonline-reloaded.net/wiki/index.php?title=Hit_ChanceFor example:
Weapon = Minigun
AC=50 (armor class of target; always different)
ST=3
PE=7
WH=0 (weapon handling perk)
STP=(7-ST+WH)*20=80 (Deduct 20% for each point of ST missing to use the weapon properly)
Hit Chance = Skill - AC - STP + (PE-2)*8 + Sharpshooter( 8 ) + Accurate ( 20 ) - 4 * TARGET_HEX_DISTANCE =
= 300 - 50 - 80 + (7-2)*8 + 0 + 20 - 4 * 35 =
= 170 + 40 + 0 + 20 - 140 = 90
for
ST=3
Hit Chance = 90%
for
ST=5
Hit Chance = 130% = 95% (After all the above modifiers your chance to hit is as low as 5%, but never above 95%)