I just bought two fairly new Taylor-tuned cattleman 5 1/2"s and have an older Uberti 7 1/2" Regulator. My first cowboy match, the Taylor-tuned Uberti's failed me. Light primer strikes left 4 or 5 to not go off and then a bunch where, I believe, the cylinder wouldn't rotate. I think the 44-40 casings wouldn't slide all the way into the cylinder thus catching on the frame and preventing rotation. I just had the cylinders lightly honed and crowned. If interested, I can let you know how they work on the second, go around.