Federal Judge issued a stay on the ATF's brace opinion. Right now until that judges ruling is overturned a braced pistol is legal to own and use. And it appears it might just have to be the a Supreme court ruling to over turn it.
Here's the Kirst conversion I did, the shorter one is a Howell conversion. They have been fun projects. the shorter one is 4-3/8ths " . Its just long enough to put a kirst conversion in and use a ejector rod.
Maybe this will help. I find it real handy being that I am new to subs or should I call it grey powder since it actually isn't black.
Black Powder Volume to Weight~Conversion Chart.xlsx