What I am having trouble understanding, and there seems to be a lot of contradictory info on, is the forcing cone angle. I have gathered that Rugers have 5 degree angles, and that the popular angle for shooting lead is 11 degrees. The Smith angles seem less clear - I have seen 8, 9 and 18 degrees. The first question is whether these angles are per side (i.e the angle between the bore centerline and the cone surface) or are the angle between the two cone surfaces, which would be twice the angle between the centerline and the cone face. Put another way, is the ruger cone 2.5 degrees between the centerline and cone face, for a total of 5 degrees. Or, is it 5 degrees each, for a total of 10? Likewise, is the 11 degree cut that is common 5.5 degrees per side for a total of 11 degrees, or is it a total of 22 degrees? Finally, does anyone know whether the Smith cone is 8-9 degrees per side, for a total around 18 degrees? The reason that that matters is that I don't want to enlarge the wide part of the cone at the cylinder gap. It is already ~0.020" larger than the throats, which I understand is about what it should be. If the existing angle is steeper/greater than the cutter angle, then the cut can be made extending the cone further into the barrel and leaving the diameter the same at the cylinder end. If the existing angle is shallower/less than the cutter, using that cutter would either leave a compound angle or enlarge the opening at the cylinder end, neither of which I am OK with. In the later case, the barrel would have to be set back and the barrel face re-cut to set the cylinder gap. That isn't likely worth it. Thanks in advance for any education on that. I am just trying to make sure I understand the mechanics there before I decide whether I am going to mess with it. If my description doesn't make sense, I can draw it out and add that. Also, if this belongs in gunsmithing, feel free to move it.