I might be contradicting myself, if so consider it a statement of error on my part... but just from Wikipedia:
Lake City Army Ammunition Plant (LCAAP) is a 3,935-acre (15.92 km2)
U.S. government-owned, contractor-operated facility in northeastern
Independence, Missouri, that was established by
Remington Arms in 1941 to manufacture and test small caliber ammunition for the
U.S. Army. The facility has remained in continuous operation except for one 5-year period following
World War II.
[1][2] As of July 2007, the plant produced nearly 1.4 billion rounds of ammunition per year.[3] In addition, Lake City performs small caliber ammunition stockpile reliability testing and has ammunition and weapon testing responsibilities as the NATO National and Regional Test Center.
Everything I ever shot in the military was LC headstamp unless it was for a foreign produced system (Gustav as an example). Lake City pretty much makes everything for the DOD, and 1.4 billion rounds a year is significantly more than what the procurement contract that was the original discussion point of the thread.
After all, that procurement contract of 900,000,000 rounds is for a duration of time, which if used to the full amount still is completely shadowed by the behemoth amount of ammunition produced by Lake City for pretty much anything in the US DOD Arsenal that fires a conventional projectile.
Pretty much (just using a 5 year contract duration, I think that this one was for longer but I can't be bothered to look at it) and even rounding up to a flat million total rounds... that's 200,000,000 rounds a year. Let's put this into perspective:
DOD ammunition
1,400,000,000
DHS contract
900,000,000
That extra zero for DOD makes a BIIIG difference. Especially taking a specifically personal thing into consideration... My USP .45 Expert has a round count from one single year, using a 750 round a day 5 days a week 30 weeks to train mean.... of 112,500 rounds. This was my last year I was at Ft. Benning and was doing a personally funded trainup for doing an AMU pistol team walk on tryout (that I ended up PCS'ing to Alaska before I could participate
). I came about those numbers because weekends I would burn about 1-2k of .45 reload, weekdays I'd visit the range would be in the 500-1000 round count and that would be pretty much every day the range was open. 30 weeks gives leeway for military related "downtime" from personal training due to field time and other military duties.
While the Federal LEO's would be better able to state exactly how much shooting goes on at FLETC for the firearms portions, I would assume that they're spending probably about the same amount of ammunition per year easily for the full capacity of the ranges that they have at their disposal, not counting continuing training.
Heck, for my Armed Guard qualification we had a 2500 rounds fired round count per weapon system that we had to qualify with (Shotgun, AR, G22) before we even actually qualified for training purposes. 50 guards on the range, 1 week, and the qualification/refresher was done for 8 weeks straight to cycle all the guards for the company through. That's a million rounds just for initial/recurring qualification training.... and it's not even counting what was authorized for resupply and training utilization at our respective central guard posts for "Sergeant's Time". Sergeants were effectively regional supervisors and could sign out ammunition for training. At least for the area I was in, he would on a pretty regular basis if guards had interest. I opted out solely because the timing always ended up being on my time off and when you live 8 hours from where you are working, it's a bit of a commute for a range day when it's done up there.