NICS checks by state by month by year from 1998 to December 2010
Click on figures to make them readable. The entire data set is available here. One interesting part of the data is the huge increase in the number of people buying guns in some states. Take Kentucky. Up through 2005, around 220,000 to 240,000 transactions for guns occurred in Kentucky (multiple guns could be purchased in any one transaction). Then in 2006 that increased to 791,599, then in 2007 to 1,587,850, then 1,881,101 in 2008, and by 2010 it was 2,385,579. After 2005 the yearly increases were sometimes twice as large as the total who had been buying guns during earlier years.
What happened starting in 2006 and kept on changing after that? One change I know of is that after July 12, 2006 those with concealed handgun permits no longer had to go through the NICS checks. That change would cause a drop in NICS checks not the massive increase. Indeed, the importance of this exemption has been increasing nationwide as more people have concealed handgun permits and this implies that the increase in gun sales shown by the NICS data actually underreports gun sales by an increasing margin over time.
But there is a solution to this mystery.
At least one state, Kentucky, appears to have recently started doing monthly NICS checks on its concealed carry permits in the summer of 2006. These monthly checks have dramatically inflated Kentucky’s NICS check numbers. Also, there are some states that that use the NICS system for background checks on gun purchases in the secondary market, such as at gun shows. In short, there are some inconsistencies in how NICS checks are used by states. For all these reasons, NICS data serves as only a rough proxy for the gun sales occurring in each state.
But on the other hand, it looks like Kentucky is not allowed to make these monthly checks.
Access to the NICS Index for purposes unrelated to NICS background checks required by the Brady Act. Access to the NICS Index for purposes unrelated to NICS background checks pursuant to 18 U.S.C. 922(t) shall be limited to uses for the purpose of:
(1) Providing information to Federal, state, or local criminal justice agencies in connection with the issuance of a firearm-related or explosives-related permit or license, including permits or licenses to possess, acquire, or transfer a firearm, or to carry a concealed firearm, or to import, manufacture, deal in, or purchase explosives; or
(2) Responding to an inquiry from the ATF in connection with a civil or criminal law enforcement activity relating to the Gun Control Act (18 U.S.C. Chapter 44) or the National Firearms Act (26 U.S.C. Chapter 53).
Something more to think about. An additional point is the 8 percent of NICS checks are "not resolved immediately" (with 5 percent presumably up to 3 days) and 3 percent take longer than three-business days. In addition, 99.9+% of those denied (about 0.8%) are false positives. At some point these costs imposed on gun transactions should be counted up. For example, a gun show may only take place over three day weekends. To have 8 percent of the NICS checks "not resolved immediately" could prevent those sales from occurring. That could be a significant effect on the cost of doing business for gun shows.