This is my last thought on this....

Gunsmithing is a trade - not a profession. As such, its a "hands on" job that requires direct training and experience to succeed. I could teach you how to build an AR15 / M16 / M4 in about 1 hour. In two days you'll be able to do this automatically.

Gunsmithing for a living is going involve a lot more than working on AR15's and M9's so is this really going to "prepare" you for your desired career?

If you're interested in the more technical aspects of weapons then you'll need to pursue a career in physics and engineering - both of which require a college education.