thanks CB, i had an FFL try tell me a person could only build 1 a yr.....IIRC, there is no limit to how many you can build for personal use. However, (once again the IIRC comes in because I'm not positive) I've always heard that the maximum that you can build and sell (even if you didn't build them with the intent of selling them) per year is 12.
I have no code references etc, that is just what I've always heard. You're gtg building for yourself, but be careful building and then selling, even if you did not build them with the intent to sell.