The federal Bureau of Alcohol, Tobacco, Firearms and Explosives has been on a tear under the administration of Attorney General Alberto Gonzalez.
Manufacturers of various products have been told in writing that their products are not a firearm and that they can be marketed outside the federal paperwork system for selling firearms. Then, months or years later, BATFE sends another letter reversing the first determination.
The Congressional Research Service found in 2005 (ATF Firearms Procedures) that BATFE has no written procedures for determining what is a firearm. The "process" is arbitrary, and the string of reversals in recent months shows how capricious a BATFE determination is.