How about the "Annual Firearms Manufacturers And Export Report" that the ATF does every year?
https://www.atf.gov/resource-center/data-statistics
Let's see now...
In 2013, there were made in the United States:
4,441,726 semi-automatic handguns,
725,282 revolvers,
3,979,570 rifles,
1,203,072 shotguns,
495,142 misc. guns.
Total: 10,844,792
Exported was 393,121
Net domestic total: 10,451,671
Total imported: 5,539,539
Grand net total: 15,991,210
Now, if you'll recall, this is the point where you tell me that just because they make them that doesn't mean they sold them. After all, a manufacturing company with overall profit margins in the single digits has TONS of money to buy TONS of raw materials, pay plenty of wages to their workers, to produce far more guns per year, year after year after year, than they can sell.
Or something like that, even though the report states on the front page "FOR PURPOSES OF THIS REPORT ONLY, "PRODUCTION" IS DEFINED AS: FIREARMS, INCLUDING SEPARATE FRAMES OR RECEIVERS, ACTIONS OR
BARRELED ACTIONS, MANUFACTURED AND DISPOSED OF IN COMMERCE
DURING THE CALENDAR YEAR."
Now let's compare to, say, 2007.
1,219,664 semi-automatic handguns
391,334 revolvers
1,610,923 rifles
645,231 shotguns
55,461 misc. guns.
Total: 3,922,613
Exported was 204,782
Net domestic total: 3,717,831
Total imported: 2,743,993
Grand net total: 6,461,824
Gee, domestic firearms manufacturing almost tripled in a six-year period. Gun imports doubled. But all those guns are just sitting in warehouses and not being sold. 
https://www.atf.gov/sites/default/files/assets/statistics/CommerceReport/firearms_commerce_annual_statistical_report_2014.pdf
https://www.atf.gov/file/3341/download
https://www.atf.gov/file/55166/download
In 2007, the ratio of NICS checks (your numbers in post#16) to guns sold in the U.S. (my numbers) was 1.73:1
In 2013, the ratio was 1.32:1. That's a pretty big difference but still indicative. Every 3 NICS checks equals about 2 guns sold.
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