CHECKING THE HEAD SPACE
When you get close, you will have to use the head space gauge. You will need to know what the correct
head space will be.
Take the action with the bolt cocked and closed, measure the distance from the inner ring, what the
barrel is butted up against, and the bolt face. Take the difference, which in this case is .100.
Now knowing the depth is .100 we can keep feeding the reamer in until the head space gauge will be
the right depth. The correct depth would be .095. Allowing for .003 for compression of the barrel to the
action, this would leave .002 on the head space, which is about right. To set the depth, use a depth
mike, placing the depth mike on the end of the head space gauge, and measuring the depth until it read
.095.
When you get close it would be best to use a dial indicator to go the final few thousands. This is how
the Mauser is chambered and head space. Other types of actions are done the same, with a little
variation.
FITTING SPRINGFIELDS
On some barrels like Springfields or Enfields, we use the same way of measuring from the front of the
action to the bolt face. Because the barrel is conned, we have to measure from the cone to the head
space gauge. This distance is subtracted from the distance from the shoulder on the barrel, to the face
of the cone.
POLISHING THE CHAMBER
After the barrel is correctly head spaced, the chamber should be finely polished. This is done with the
lathe running at a high RPM.