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Fabricating a Custom Front Sight
by Roy Seifert

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Disclaimer:  This article is for entertainment only and is not to be used in lieu of a qualified gunsmith.  Please defer all firearms work to a qualified gunsmith.  Any loads mentioned in this article are my loads for my guns and have been carefully worked up using established guidelines and special tools.  The author assumes no responsibility or liability for use of these loads, or use or misuse of this article.  Please note that I am not a professional gunsmith, just a shooting enthusiast and hobbyist, as well as a tinkerer.  This article explains work that I performed to my guns without the assistance of a qualified gunsmith.  Some procedures described in this article require special tools and cannot/should not be performed without them.

Warning:  Disassembling and tinkering with your firearm may void the warranty.  I claim no responsibility for use or misuse of this article.  Again, this article is for entertainment purposes only!

Tools and firearms are the trademark/service mark or registered trademark of their respective manufacturers.

Navy Arms 1892
My long-time shooting buddy, Jon (a.k.a. “Lone Star”) has a beautiful stainless steel Navy Arms replica of a Winchester 1892 in .45 Long Colt caliber with a twenty-inch octagon barrel.  He recently installed a tang peep sight which he uses as a ghost ring by removing the aperture.  Unfortunately, he couldn’t get the new sight low enough, which meant the rifle was shooting high.  It was alright for “minute of cowboy”, but he wanted to be able to adjust the sights to hit to point of aim.  Since the peep sight couldn’t go any lower, that meant we would have to raise the front sight.  The rule is; move the rear sight in the same direction you want the bullet to go, move the front sight in the opposite direction you want the bullet to go.

I have a number of spare sights in my parts bin, but none of them would fit.  Apparently Navy Arms used a non-standard dovetail that was wider than 3/8.  Jon also mentioned that he didn’t necessarily need a beaded front sight.  So I decided to fabricate a square post front sight for him using my MAXNC 10 CL CNC hobby mill.

I ordered a 1/8” x 3/4” x 12” piece of steel bar stock from, my favorite place to purchase metal.  This would become both the base and front post for the new sight.

I used CorelDRAW® to design the pattern for the sight base and post.  I like using CorelDRAW® because I have greater design control, and I am very fluent in its use.  In the above figure the square in the middle of the base is for the notch that will hold the post.

Now for some math; I used my Front Sight Height Calculator to calculate the increase in front sight height.  Jon needed to move his shots down 6-inches at 25-yards.  The increase in front sight height would be 0.170 inches.  His front sight measured 0.328” which meant the new sight would have to measure 0.498”; which we rounded up to 0.500”.  His base measured 0.515” wide and the dovetail was 0.389” wide (much wider than a standard 3/8” 0.375” dovetail) and the base thickness measured 0.113”.  0.500” – 0.113” = 0.337” which would be the height of the new front post.  I also milled a notch in the base which allowed me to keep the post straight when silver-soldering it to the base.

I wanted the total height of the sight to be 0.500”.  Since the dovetail was 0.113”, that meant I needed the front post to be 0.337” in height.  Remember, sight height includes the thickness of the dovetail.  Using these measurements I created the machine “G” code for my hobby CNC mill.

I exported my design as a drawing .dwg file, which I imported into my CAD/CAM software BobCAD-CAM.  I planned to perform the milling with a 1/16-inch square end bit, so I created the tool paths offset by 0.0313, or half the diameter of the 1/16 bit.  The purple lines in the above figure are the tool paths.  For the post and base the tool path was offset to cut outside; for the notch in the center of the base, the tool path was offset to cut inside.  The multiple lines on top of the base were for milling the thickness of the base down to 0.113".

After the parts were milled they had some rough edges.  I took a flat jewelers file and some 400-grit wet/dry sand paper to trim the flashing.  I used a Cratex bit and my high-speed rotary tool to polish the sharp edges on the base. 

Now I assembled the two pieces by silver-soldering them together.  First I cleaned each surface to be soldered, held the part with a pair of needle-nose pliers over a propane torch, and when the metal got hot enough, tinned the mating surface with the solder.  The part needed to be hot enough so the solder would melt, flow and stick; if the part was too hot the solder would bead up and run off, if too cool the solder wouldn’t melt.  While the solder was still molten I used a brush to wipe off the excess solder.

Now that each part was properly tinned I inserted the post into the notch, held the parts together with pliers, then held the assembly in the propane flame so the solder on the parts would melt and hold them together.  I also ran a bead of solder along the joint so it would flow down into the seam.  You can see the soldered seam in the above photo.  The metal turned dark when I applied heat to the pieces.  I allowed the assembled sight to cool to room temperature without artificial quenching.  If the part is cooled too quickly the silver solder can become brittle and the part could come apart.  After the sight cooled I took a flat jewelers file and removed the excess solder from the corner of the joint.

Milling the Dovetail Angles


So now I had an assembled sight, but the base was square; I still needed to mill the angles for the dovetail.  I mounted the sight upside-down in my machinist vise on my table-top mill.  I installed a 65-degree dovetail cutter I purchased from Brownells, set the depth so the bottom of the cutter was riding on the bottom of the post, then ran the cutter along the front edge of the base thereby cutting the correct dovetail angle.  I cut the rear edge the same way.

Final Finish
The sight was still discolored by the heat from the soldering process, so I took the sight to my blasting cabinet and beat-blasted it clean.  The bead blasting removed the discoloration and left an even, matt finish.

Now the sight was ready to be blued.  I’ve had great success using Van’s Instant Gun Blue.  This is the best, and probably most difficult cold-bluing product to use.  It really isn’t very “instant”!  This product produces the closest result to hot bluing and I’ve discovered it is the best product to use for bluing larger areas.  Using vinyl gloves so my bare hands wouldn’t touch the sight, I thoroughly degreased the sight using acetone.  I poured some Van’s Instant Gun Blue into a small aluminum pan and immersed the sight into the solution so that it was completely covered.  After 5 minutes I removed the sight.  As you can see in the above photo the sight came out with a deep, rich, even blue/black color.  I wiped the sight clean and coated it with gun oil to stop the bluing process and to protect the sight.  

I used a 65-degree dovetail file to fit the new sight into the dovetail on the barrel.  Notice how high the post sits above the barrel.  This was because I measured the thickness of the original sight base instead of the dovetail in the barrel.

Marlin® 39A
Jon’s sight came out so well I decided to make one for my Marlin® 39A .22 lever-action rifle.  Like Jon’s rifle, this rifle came with a bead front sight which I wanted to replace with a square post.  Jon uses his rifle for Cowboy Action Shooting™ so he couldn’t have any color on his sight.  On my sight I decided to put a vertical white line which seems to be popular for ghost-ring sights.

Brownells sells a post front sight with a white line in the center for $30.  Using parts I had on hand mine cost much less.  I used the 1/8” x 3/4” x 12” piece of steel bar stock for the post as I did with Jon’s rifle.  Brownells sells a 12-inch piece of 3/8” dovetail blank which I used as the base; this way I didn’t have to cut the dovetail angles.

The dovetail for Jon’s rifle was cut into the barrel.  Barrel-mounted front sights use a longer dovetail; Jon’s measured 0.538”.  The front sight for my Marlin® 39A was mounted to a ramp.  Barrel ramps still use a 3/8” dovetail, but with a shorter length.  My Marlin® front sight measured 0.437”.  The thickness of the base measured 0.087”.  Since I was cutting the base from 0.125” thick dovetail stock, the depth of the notch needed to be 0.038”.  The total height of the sight was 0.265” so the post was 0.178” high.  

I again used CorelDraw® to design the front post, then exported the pattern to my CAD/CAM program.  I used my hobby CNC mill to cut a channel in the base for the post, and to cut out the base from the dovetail blank.  I also used the CNC mill to cut out the post from the 1/8-inch bar stock.  I silver-soldered the post into the channel I milled in the base, then milled a 3/64 groove in the front ramp of the post.  I bead-blasted the new sight, cold-blued it as previously described, then applied white appliance touch-up paint to the groove.

The dovetail base was just slightly larger than the dovetail in the barrel ramp.  I used my 65-degree dovetail file to file one side of the sight base until it fit.  The top of the base is higher than the top of the ramp, but the base of the post sets on top of the ramp with no unsightly gap.

Ruger® Bisley Blackhawk®
My Ruger® Bisley Blackhawk® required a higher front sight.  Since the original front sight was 1/8“ thick, I fabricated my own, higher front sight blade.  Instead of using steel and bluing the sight, I fabricated it out of brass.  Refer to my article Fabricating and Installing a Taller Front Sight for a Ruger® Bisley Blackhawk®.

I again used CorelDRAW® to design the pattern for my new front sight blade.  The height was 0.495” but I designed it with an undercut front to reduce glare, rather than a post or ramp.

I purchased a piece of brass 1/8” x 3/4“ x 12” from  I decided to fabricate the new blade out of brass because it’s easier to work with.  I realize that since brass is softer than steel the new blade could get deformed easier, but I’ve had steel blades get deformed by being knocked around, plus I can always make a new one.  I’m really not that hard on my guns so the brass blade should be just as durable as a steel one.  Plus, I don’t have to worry about finishing the brass.  However, I could, if necessary, produce a blade made of steel using the steel bar stock instead of brass.  I took the piece of brass, mounted it to a piece of wood on my milling table, and milled out the new blade.

After I milled the new blade I touched up the sharp edges with a jeweler’s file and installed it in the front sight base.  I took a 1/16” drill bit and using the hole in the sight base as a guide, drilled the roll pin hole in the new blade.  After I drilled the hole I installed the roll pin.

Tactical Solutions 1911 .22 Conversion Kit
I have a 1911 .22 Conversion Kit that I purchased many years ago.  This was the same kit on which I installed a fixed ejector, refer to my article Resurrecting a 1911 .22 Conversion Unit.  This kit is currently manufactured by Tactical Solutions which comes with an adjustable rear sight, but my original kit had fixed sights.  In order to prevent the hammer from hitting the rear sight I had to install a high profile Millett adjustable sight which they no longer manufacture.  That meant I would also have to install a higher front sight.

My measurements for this new front sight were as follows:

Bar stock thickness:  0.123”
Dovetail depth:        0.085”
Dovetail width:         0.330”
Dovetail length:        0.452”
Height of post:         0.360” as measured from the top of the slide to the top of
                                       the post.
Width of notch:        0.123”
Depth of notch:        0.123 – 0.085 = 0.038”
Final height of post:  0.085 + 0.360 = 0.445”

I followed the same procedure as I did for Jon’s rifle using the above measurements to fabricate the base and post.  The above photo shows the installed taller front sight.

With the proper tools and materials I can now fabricate custom front sights pretty much made to order.  I think the next time I fabricate a custom front sight, I will mill the base so it is the proper thickness, then mill a notch for the post.  I would mill a tab on the bottom of the post that would set in the notch.  I still like the channel because it helps me to get the post soldered straight.  In fact, if I made the notch deeper I could attach the post in the same way some front sight posts are attached to a 1911 slide.



   © Copyright 2010 Roy Seifert.