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A 6.5x55 Match Rifle
Page 4
Well, up to this point I have been using a borrowed bolt, but that one had to go home. I had lapped the lugs and head spaced using a straight handled Turk bolt, so I forged the handle using a set of bending blocks. As noted, this left the handle a little short, so I made some mods to allow for a better grip.
First I ground the bolt knob with a flat facing down. This provides a space to allow the fingers to slip under the knob. Note that the flat does not extend far enough to merge with the stem.
Then I checkered the flat so as to offer a better non-slip grip.
These are the tools used to checker metal. Uppermost is a thread pitch gauge, not really required, the Brownells Checkering File, and at the bottom, a triangular or three cornered file.
Brownells sell Checkering files designed to provide a line pattern of 20 to 75 Lines Per Inch (LPI). The one pictured is a 20 LPI file as determined by the Thread Pitch Gauge. See how the lines of file teeth match the teeth cut into the Thread Gauge? On the left is the triangular file. (Brownells gets between $26 and $32 EACH for these files. I used the 20 LPI and think maybe a 30 LIP would be OK, but anything finer is real smooth, and I think a lot of practice would be required for the finer files. These are intended as line layout files only, most of the metal is to be removed with the much cheaper triangular file.)
The bolt knob is held in a copper protected set of vise jaws. The cardboard on either side has two red lines drawn at 30 degrees to each other. As I am doing the underside of the knob, the exact angle is not real important.
The flat extends slightly above the vise jaws and cardboard strips.
The Checkering file is lined up with the one of the red guidelines (it really is lined up, the camera makes it look funny) and a pattern of lines are produced.
These lines are deepened a little more with the Checkering file and then deepened a LOT with the triangular file.
As the lines are developed, the Checkering file is used to widen the pattern of lines until they cover the width of the flat. The additional lines are made one at a time by moving the checkering file one line width to the left or right, letting the file be guided by the lines already developed.
Once the pattern is developed, a second set of lines is started in the other direction, using the other red guideline.
This set is deepened with the triangular file and widened as before. All the lines, in both directions, are deepened with the triangular file, and touched up with the checkering file until the flat is covered with a deep and continuous line pattern.