A while back, there were some cast bullet guys "trying something new" in the way of bullet coatings. At first they were applying powder coat with a powder coat gun followed by baking. Performance was good, but the method had room for improvement. Then they figured out that they could put bullets, air soft BBs and powder coat powder into a plastic tub, shake and the powder would adhere. Again the bullet is then baked to get a great coating. This was a huge leap forward in the ability to easily get more powerful cast bullet loads without leading.
After powder coat became common with cast bullet guys, Federal jumped in with a factory load that duplicates what the cast bullet individuals were doing. They can get good ammo performance without the cost of actual copper jackets.