There's fact and error in all these comments, maybe even mine.
A. "Who cares if they are gifts for others? That's perfectly legal. Gifting a firearm does not make it a straw purchase... "
Bona fide gift is a valid use for a firearm bought with your own money.
B. "A lot of folks don't understand that in order for it to be a "straw purchase" the person you gift it to cannot legally purchase that same firearm."
For it to be a straw purchase, you are buying the gun for the other person so their name does not appear on the 4473 as purchaser of record.
C. "You can buy a firearm with the original intent to gift? That's news to me! I thought the form asks if you are purchasing for your own use? Same for handguns? "
Bona fide gift is a valid use for a firearm bought with your own money.
D. "You can also find the information on page 156 of the guide:
https://www.atf.gov/resource-center/docs/atf-p-5300-4pdf/download"
The page number is 165. Everyone should follow those links, save copies of Federal Firearms Form 4473 and Federal Firearms Regulations Reference Guide, to read and know yourself and to show to or to share with any one who complains of "no gun laws".
E. "Sorry to throw a monkey wrench in your assumption OP ..."
Counting NICS checks as a proxy for 4473 transactions does not tell you the number of guns sold. The 4473 has multiple lines for gun descriptions (and you can attach a page with descriptions beyond those on the 4473: you can buy an entire gun collection on one 4473 with one background check).
Usually multiple purchases are more modest. I bought a revolver and shotgun as gifts for my wife Nov 1998, one 4473, one TICS/NICS background check. My son bought matching M70AB2 rifles, one for himself and one for me as a belated and complete surprise birthday gift Mar 2006, one 4473, one TICS/NICS background check.
Both cases we were warned that buying guns of identical make, model, caliber required reporting the sales and could delay future purchases if authorities decided a pattern suggestive of straw purchase for resell showed in our buying habits (special places like the TN/VA border have special rules). I shudda asked if it were a federal or state reporting requirement.