The banking regulations on this topic are very clear.
Any cash deposit or withdrwal of more than $10,000 must be reported -- except for those businesses that have a specific exemption; due to paperwork previously submitted and approved. The exception applies to businesses that deal regularly with that bank or credit union and regularly have high volume cash transactions such as supermarkets, liquor stores, amusement parks, etc.
There is a another federal requirement that these same financial institutions must report any "suspicous transaction" -- regardless of amount -- if the financial institution suspects illegal activity.
The supposed intent of these regulations was to help police catch drug dealers, money launderers, and tax cheaters. Most of the bankers I regularly work with have not found these regulations to be onerous. Likewise, we also haven't seen very many successful prosecutions result from these regulations. Crooks don't walk into our lobbies and try to deposit large amounts of cash.
While someone's ego may be tender, these banking regulations have very little to do with the purchase and sale of firearms by honest citizens.
