I don't disbelieve you for an instant, but do you have a source for that? I'm sure that I will be asked when I use it.
I just can't imagine anyone picking up a new rifle without at least one box of 20; or a new pistol without at least one box of 50.
The discusion has come up on The High Road a few times over the years. Here's one link from there for 1997 data.
http://www.census.gov/prod/ec97/97m3329f.pdf . Table 6a on page 15 has the data for 1997