I usually get my bullets at the Sierra Factory, in Sedalia Missouri. (Factory seconds) Problem is, they are out of .45 ACP and are not planning on running until sometime in late Jan or early Feb.
They just finished the hunting season (Rifle Bullets), still have to keep up with the Lake City Ammo Plant orders and find time in between to get back to what I need.
Although I do not know the actual numbers, they may run, for example, the machines long enough to produce 60 Million bullets in caliber X, then they have to reset the dies and make them in caliber Y, then repeat for the next caliber (And each caliber gets three or four different weights).
AND, before they will release the bullets for sale, they have to go through quality control checks that include hand inspection and firing a test batch for each run of bullets they make.
If any of you ever get a chance to actually tour a bullet factory or a cartridge manufacturing factory, jump at the chance. I have toured the Sierra Factory and the Starline Brass in Sedalia MO. I also got a chance to tour Missouri Bullets, Kingsville Missouri. You will see employees and machines going full bore. (No pun intended)
The holidays also slowed them down quite a bit, as pesky employees really want to spend time with their family.