If I recall correctly, didn't Waco happen because a feeb asked someone to cut a shotgun barrel too short? Mossberg 500 security barrels have been hard to find and a couple years ago I bought one from a guy who had cut down a longer barrel. I've never put a bead on it, and would like to put a bead on it. But I'm paranoid about the length.

Where, exactly, do you measure from? Or, if you know, what would the longest measurement on it have to be for it to be legal? I'd like it to be a quarter inch too long just to be safe, but I sure don't want it too short. Thank you!