I just read this:

FYI – we have just received the following message from Vista Outdoors (the parent company of Alliant Powders):
“Due to the worldwide shortage of nitrocellulose, the Vista Outdoor supply agreement for the sale of Alliant Powder canisters has been suspended for an unknown period. At this time, we have no timeline for the fulfillment and will be canceling outstanding Alliant orders in our system.
Representatives will provide updates and coordinate new orders based on availability.”