It will not shoot worse. Reaming the cylinder throats to .4525 will only help when shooting lead. Will not help jacketed as much, except to lower the pressure a bit. Not only does reaming correct the throat size, it also trues up the throats. With my Vaquero, the group size was cut in half. With the BH, not quite as much, but still tightened the group. Also the leading was less. My reamer has paid for it self as I have reamed a couple of others for friends and 3 of the 4 cylinders of my two new flattop convertibles needed reaming as well.think you might be en route to making your revolver shoot worse than it does at present.