I've noticed that when i run with a very good active full squad , i get a lot of Battlepacks each match.
some people say it's just random, and yes some of it is, but one match 3 of the 5 in our squad got them, we were the top squad in points.
and when we played well as a good squad someone always got one in our squad each match.
now this took a good squad leader and members to follow orders from defending important objectives like the one that spawned air planes and tanks, also attacking orders being issued when we were capping an objective.
So make sure to squad up, do not be in a locked solo or no squad , get in to a squad , make sure the squad leader keeps issuing defend and attacks at the right time, and under 60 second intervals . This is what you need to do, because of this i've unlocked one of the puzzles and have many legendary skins.
so remember Squad up , issue those commands at the right time, and play the objective, you will be rewarded well in score and battlepacks.