You can post the answer to your own question. If you just learned this you are out of you league.
The difference between the two BCGs is the presence of a full auto lug. The bottom portion of the BCG has a lug that contacts the sear release in a full auto trigger groups and allows the gun to fire in fully automatic. Since a standard AR 15 does not have the trigger components to fire full auto the presence of the full auto lug does not allow a standard AR 15 to fire full auto.
No full auto or no burst and you do not have a assault weapon designed for the battlefield.