I have a friend who had never bought a gun before, but wanted a Mosin from fleet farm. Not anticipating any problems, he went in and tried to purchase one, but his background check was not immediately approved, and the clerk told him that the ATF would have an answer for him in 48 hours. The answer came back the next day as a "No." He called me, the "gun guy," and asked me for my input on why. After asking him about any felonies, domestics, or restraining orders, (no to all), we got to his mental health history. He told me he WAS court ordered to undergo a psychological evaluation, and was originally diagnosed with borderline personality disorder, but then after a reevaluation, was diagnosed with intermediate explosive disorder, with the original diagnosis being thrown out. As the language states, you can be denied for having a mental disorder which makes you a danger to yourself or others, but ALSO it states that you must be found "insane" as well. Now, Intermediate Explosive and Borderline Personality both fall into the "danger to yourself or others" category, but are not, as far as i know, diagnoses of insanity. I wish there was a comprehensive list of mental illnesses/disorders that would bar a person from buying a firearm. Any help on this is appreciated.