It should work with just
PHP Code:
cs_set_weapon_ammo(give_item(id, "weapon_awp"), 1)
bpammo is automaticly at 0 when item is given, therefore unnecessary
Check for plugin which can reset your weapon bpammo, there's no other way for it to do so
EDIT:
Answered a bit late.
You should know which plugin might, because we have 0 clue.