You sign piece of paper at your time of purchase where they tell you this information. I bought my Mossberg 930SPX from the PX at Benning.
Dude I'm raising the bs flag here. There is no paper, and they don't say anything. I just bought a pistol 2 days ago. That disclaimer is just there to cover their ass. The same rules apply for buying and selling of firearms. If I decide to sell it tomorrow I'm good. Now if I started to buy a lot at a time and turned them for a profit then yes that would be illegal.

