The machinery required for button rifling is similar to that required for broaching, or cut rifling. With the
exception that far more power is required for operation with the buttoning process. Because of the high
speed at which button rifling may be done, a single machine can turn out many times the maximum
number of finish barrels produced by banks of rifling machines.
The normal time including setting up to rifle a barrel with buttons is about 3 minutes. There is another
process that is used along with button rifling, and that is button reaming. Most button rifling processes
call for button reaming, or cold sizing of the bore surface.
By button reaming, you can keep a precise bore size from one barrel to another. This area becomes the
top of the lands. This is the same as the rifling button with the exception that it doesn't have any grooves
cut into it. It purposes is to size the barrel and to close the pores in the metal. This button is usually made
.0015 larger than the finish bore. The metal will close back about .0015 after the button passes through
it.
The pull method for rifling seems to be more popular, and must to have the lead on the button exactly
matched to the lead on the head of the rifling machine doing the pulling. However, there is another way
to make the machine so you can use thrust bearings to allow the button to rotate in the bore. More on
this later.