If you are careful, you can use the standard high-speed center. Put a little grease on it that contains
MolyKote Z before setting it up.
I have tried to use live centers off and on, but I have found that I get to much chatter, and that will cause
stress to build in the barrel, and thus warp the barrel.
It is very important to keep any stress from build up in the barrel (Live centers, too tight centers, dull tool
bit, improperly sharpened tool bit, etc.) Now for the tool bit. I have used carbide most all the time in
turning barrels. I prefer a good grade of high-speed steel as they are sharper and cut better, but require
sharpening every pass, to keep a good edge. I had to use carbide due to the time saved.
I ground all my tools to the general shape. On high-speed bits I used only about .010-nose radius,
stoned on by hand. Set the tool up so it is about .010 above the tail stock center. If I have the time, I
usually use a feed of .004, but you will need to experiment to see which feed works the best. Usually I do
not take over .020 passes per each side on each pass.
What you have to watch for is that the cut is not heavy enough that it will cause the barrel to spring,
especially on the barrel that is half way turned down. This springing causes stress. The tool must cut
clean, for if it drags, or it is slightly dull it will cause the barrel to heat as it is turned. When the bit is
sharpened right you will get some heat build up, but not much. Watch the chips, as they are coming off
the barrel. If they turn a dark blue, you are taking too much a cut, or the tool is dull.
Keep close watch on the pressure of the tail stock. It must be snug on the barrel, but not tight. As the
barrel heats, it lengthens, and the tail stock must be loosened. If the tail stock center loosens too much,
the tool bit will chatter. After the contour is turned up to where the shoulder will end, you will need to
remove the barrel. You will then check to see if the bore is straight, and straighten if necessary.