There is a rare Apex Pack animation causing the Pack to "blast off" after dropping all three items.
The first Prime Gaming Loot included 5 Apex Packs alongside the Omega Point Pathfinder skin, available in February 2019 with the release of Apex Legends. They are spread out in the following way: Up to 199 Rare Packs can be earned by leveling up. Collection Event Packs can be purchased for 700 each during a Collection Event, or purchased from bundles. Legendary and Thematic Packs may also be offered in the store, often bundled with other items, otherwise they are offered as a standalone purchase for respectively 500 and 400 each. The Store always sells Rare Packs in their own "Apex Packs" section, costing 100 each.
When Heirloom Shards are found, the Pack is not consumed.
Collection Event Packs do not count towards this, and Heirloom Shards cannot be found in them.
Heirloom Shards are guaranteed to drop in the next Pack after 499 Packs are opened without finding any, unless all Heirloom Sets are already owned or the total amount of Heirloom Shards already in possession are enough to buy every Heirloom Set currently available in the Heirloom Store.
Collection Event Packs and Thematic Packs do not count towards this.
A Legendary item is guaranteed to drop in the next Pack after 29 Packs are opened without finding any.
Rare items not already in possession take priority over Rare duplicates, which is why Rare Crafting Metals are harder to find compared to the other rarities since Common, Epic, and Legendary items instead are fully random.
The chance for more Rare items to drop could be around 50%, but this is just an estimate.
There is no reported chance for a Rare item to drop outside of the 100% chance in Rare Apex Packs.
If the case of Collection Event Packs and Event Thematic Packs, if somehow all event items are owned before opening one, all the Pack contents will be replaced by an amount of Coins equal to the Pack cost.
If an item already owned is chosen to drop again, it'll be converted in Crafting Metals. These are the chances for at least one item to drop in higher quality than Common. The categories from which the items contained in the standard pool are pulled from are listed as following: