The barrel is a SS PacNor that was originally 20" HBAR profile and chambered in 5.7X28 but the original owner had the gas port put in the standard rifle location. I got the barrel for $40 and plugged the original gas port, shortened it to 18", and put in the pistol length gas port. I did the bolt by installing a ring to decrease the bolt face size and then cut out the area for the ejector and modified the extractor a bit.
This is a picture of the bolt face;
There is a bit of other work that must be done to allow the bolt and carrier to slide through the FN pistol magazine feed lips but they are minor compaired to building the bolt. The rifle shoots just like a standard AR except much much cheaper to reload for and it puts the brass in a nice pile at about 5:00 O'clock, about 6 feet behind me. The side cocker handle is from when I first built the rifle and used it first as a straight pull bolt rifle for testing.
Radd, I didn't mean to get into your post I only meant to show there was another way (maybe) to get a California legal 10 round limit with out all the locks and stuff. I won't go any further.