FRONT SIGHT INSTALLATION
The front sight is attached by three 6-48 Torx machine screws with a hole
spacing of 0.120”. In a well equipped shop the installation might be
accomplished using a mill equipped with a quill depth gauge, a V-block, and a
sturdy mill vise. Many shops do not have the mill, but most have a drill
press, and perfect installations can be accomplished. These instructions are
directed to the drill press installation.
Our transfer punch, $17.00, is recommended for hole location. There is not
enough material in the sight base to support a drill and use the base as a
guide. Lacking the punch, the hole centers can determined by using the sight
base as a scribe guide. No matter what method is used, I recommend drilling
and tapping the center hole first, securing the sight before locating the
other two.
Make up a drill stop and a tap stop by making disks about 3/8”diameter x ¼”
thick from round stock. Drill a #31 hole in the center of one for the drill
stop, to be secured by a #6 set screw from the outer diameter to the center.
Drill and tap the other 6-48, secured as the drill stop with a #6 set screw.
Wrap the barrel with a layer of 20 pound copy paper to protect the finish and
provide more secure clamping. Use an inexpensive V-block to clamp the barrel.
Low cost V-blocks can be purchased from many tooling suppliers. ENCO is one I
have used 800-873-3626, www.use-enco.com.
Use a small piece of sheet metal under the clamping screw to prevent tearing
through the paper.
Square the gun in the vise by using the grip frame as a reference. Keeping the
transfer punch perpendicular, locate and center punch the middle hole. Secure
the drill stop on a #31 H.S. drill, adjusted to drill 0.095” to 0.100”
deep. Tap in the drill press. Use either a center for the tap wrench or the
B-Square Tru Tapper to keep everything straight, and avoid broken taps. Adjust
the tap stop to 0.090 to .095 and tap first with 6-48 plug tap followed by a
bottoming tap. Clean the hole of chips, and attach the sight base, being sure
the provided Torx screw bottoms on the sight, and not the hole. Locate the
front and rear holes; drilling and tapping as above.
Clean the holes of chips and oil using a Q-Tip and solvent (MEK or acetone).
Clean the screws with the solvent and assure all three screws bottom on the
sight. Attach the sight with Red Loctite. Tighten securely, but do not over
tighten. There is danger of the bit stripping in the Torx head. If the sight
must be removed in the future, heat to approximately 350F. This temperature
will not change the temper of the barrel or discolor the finish, and will
allow the removal of the Torx screws without the Torx bit stripping.
If the front blade is not the correct height, it can be exchanged for a
different one as long as the original blade has not been altered. I can help
if you enclose a note stating the error, range, and sight radius. The blades
are offered in heights from 0.200” to 0.350” in 0.050” increments.
Any problems with the installation please call. As Dillon has said, “Don’t
suffer in silence”.