Note: This procedure involves editing a game file; create a backup
copy of the file before proceeding. Use a text editor to edit the 
"ETIAssaultRifle.cfg" file in the 
"/Program Files/Khaeon/Alpha Black Zero/Livingsword/Weapons/" directory.

Change the following lines: 
// Bullets per clip
AMMO_PER_CLIP : 75

// Maximum amount of bullets
MAXIMUM_AMMO_LOAD : 375

to... 

// Bullets per clip
AMMO_PER_CLIP : 99999

// Maximum amount of bullets
MAXIMUM_AMMO_LOAD : 999999