Noticed you were giving ammo via actually giving the item. You can set bp ammo using a native from cstrike.
PHP Code:
new g_WeaponBPAmmo[] =
{
0, 52, 0, 90, 1, 32, 1, 100, 90, 1, 120, 100, 100, 90, 90, 90, 100, 120, 30, 120, 200, 32, 90, 120, 90, 2, 35, 90, 90, 0, 100
};
cs_set_user_bpammo(id, iWeapon, g_WeaponBPAmmo[iWeapon])
iWeapon is the CSW weapon constraint. like CSW_M4A1