"It's actually mind-boggling," said Karen Davies, Lake City's manager.
The question is, for how long? Although no one knows when the conflicts in Iraq and Afghanistan will end, Ms. Davies and other ammunition industry executives understand the heavy orders won't last forever.
So as they churn out the military's most essential pieces of hardware, ammunition makers are preparing for a downturn in business.
They worry about a return to the post-Cold War period when the Pentagon slashed spending for small-caliber rifle rounds and other munitions, forcing suppliers to cut payrolls, mothball manufacturing equipment, lose environmental permits and close their doors.
"The demand is fast when it comes, and then it can drop off very quickly," Ms. Davies said.
After the Sept. 11 attacks, the need for ammunition spiked; the Pentagon raced to meet requirements. Nearly $93 million in taxpayer money was spent overhauling domestic facilities. Foreign suppliers were called in to fill the gaps.
Military officials now talk about a need to protect the industrial base but say it makes no sense to spend money for unneeded bullets and bombs.
"We have to recognize we aren't producing ammunition for the sake of producing ammunition," said Bob Kowalski, business manager for maneuver ammunition systems at the Army's Picatinny Arsenal in northwest New Jersey.
While tanks and aircraft carriers dominate the public's attention, the military would be unable to fight without rifle cartridges, grenades, mortars and other explosives lacking the cachet of their costlier cousins.
Making this firepower is a network of facilities that has changed drastically in the past three decades.
In 1978, there were 318 plants in the United States involved in ammunition production. By 1995, six years after the Berlin Wall fell, there were fewer than 100, according to Loren Thompson, a defense analyst with the Lexington Institute in Arlington, Va.
U.S. spending for ammunition dropped 78 percent.
"Anytime the industry shrinks, you lose expertise and skill," said Mr. Thompson, who has co-authored a study of the ammunition industry.
Officials at the military's Joint Munitions Command in Rock Island, Ill., said there are now more than 170 commercial ammunition companies.
Adding to that base are 10 weapons production plants, including Lake City, which are owned by the government but managed by contractors. Three others are owned and run by the government.
Of these 13 facilities, four will close by 2011, victims of the Pentagon's 2005 military base closing round.
Built in 1941, Lake City is operated by Alliant Techsystems, an Edina, Minn. multibillion-dollar weapons company.
Spread over nearly 4,000 acres, Lake City is the largest producer of the small-caliber ammunition used by the Army and the other military branches. General Dynamics manufactures an additional 300 million rounds a year.
The bullets come in different types and sizes; the 5.56-mm round, used in the standard-issue M-16 rifle, is the most frequently fired by U.S. forces.
When Alliant began managing Lake City in April 2000, it had 650 employees there making 350 million small-caliber rounds annually. After the United States invaded Afghanistan, orders increased.
More than 2,500 workers in Lake City now make four times as much ammunition as they did seven years ago. Current output is 120 million rounds a month - nearly 4 million bullets a day.