Why you didn't use the original natives? If you use give_item then you must not check the backpack ammo.
PHP Code:
#define PLUGIN "Nade Giver or something else"
#define AUTHOR "me"
#define VERSION "0.1"
#include <amxmodx>
#include <fun>
public plugin_init(){
register_plugin(PLUGIN, VERSION, AUTHOR)
}
public client_death(iKiller, iVictim, iWeapon, iHitplace, TK){
if (!TK && is_user_alive(iKiller)){
if (iWeapon == CSW_HEGRENADE){
give_item(iKiller, "weapon_hegrenade")
}
}
}