Indeed, 9x19. I have an FDM machine. The parts, while seemingly "strong" for most decorative or light-use applications, are absolutely terrible when given a real workout.
There isn't enough money in this world to convince me to fire the type of FDM-printed 'gun' that the gun-grabbers think we're all mass-producing in our basements.
In addition, I had a lot of parts 'printed' in metal for a few years -- more specifically, mostly SLS printed parts that were then 'infiltrated' with another metal during a casting process (bronze, I believe? -- Shapeways was the source).
They're strong. Very strong. ...But not strong enough that I'd ever trust my life to one.
And, most importantly, the handling required between sintering and infiltration, combined with the casting process, means a lot of shrinkage and unpredictable warpage.
You can 'print' 500 of the same part, and every single one of them will be different; with about 30% of them failing to meet specs, if you're shooting for a tolerance better than +/- 10%.
Roamin_Wade, materials range from PLA (a corn-based plastic), to nylon, to ABS, to flexible polymers. Cost varies greatly.
The Defense Distributed 'Liberator' might cost less than $2 to print with cheap PLA. Or, it might cost $20+ in some higher end polymers.
The above is based on FDM printers, however. (Fused Deposition Manufacturing) If you turn to SLS, SLA, or any of the other laser-based systems, cost goes up exponentially (for materials and the machine), and the parts are generally extremely brittle unless put through special processes and heat-treating.