This was on their website;
Brownells Ammo Information
AMMO NEWS UPDATE 12/11/12
We recently met with representatives from Federal Premium Ammunition, and they are working diligently through every channel they have to ease the current shortages. However, the shortages will most likely be with us for some time. The Lake City ammunition plant that produces this ammo is first and foremost a government production facility. It is used to manufacture ammunition for the commercial market only when excess capacity is available after the governments orders are filled. The problem right now is that both government and commercial demand are high. Government demand must be fulfilled first, so Federals hands are somewhat tied in terms of ramping up commercial production.
When commercial ammo is produced, Federal feeds it into the supply chain, and they assure us that Brownells is well positioned in line for allocations. But for now deliveries will be modest at best. This situation is not likely to change dramatically in the next 60 days.
As a result, we are seeking out alternate sources of this military type ammunition, and as we acquire inventory we offer it to our customers with backorders in the order their original orders were received. Many of our customers have already received e-mails offering them an alternate to the backordered product.
We continue to communicate daily with the Federal folks, and will post here any additional news as soon as we receive it.