Billings' Choke rounds were our duty load when we got serious with our patrol shotgun program in 2003. They worked great for a while, including a few shootings.. When Federal bought the design from him, they worked as usual for a time, then we started getting horrendous, keyholing frisbee fliers. We complained to Billings himself, who tried to produce the ammo for us again, but we got the same fliers – apparently something had changed with the wad production, and he never could get it dialed in again (we subsequently changed to LE133 and LEB127 slugs). I still have a stash of the Choke stuff but I don't trust it for anything but practice.