I also wished to get a real bullet effect.. Hard core mod is not very customizable.. My solution came with this weapon editor
http://www.gta4-mods.com/tools/gta-iv-weapon-editor-f1827
It edits the weaponinfo.xml file in data folder.. U can do that manually but its dificult.. This software allows u to edit any weapon bullet damage, rate of fire, range, magzine size etc..
Loved it.. Hope it helps u.. I would like to know your remarks on it :)