Dovetail, continued

 

 I am only concerned with making a rough front sight that will be used to sight the gun in and then be polished up as the final step.

 

Equipment needed:

  • A sturdy drill press.

  • A cross-sliding vise.

  • A Dovetail Cutting bit.

  • An End Mill Bit

     I began this project with some brass stock I purchased in the plumbing department of the local hardware store.  Figure 1 shows one of the brass pipe plugs alongside the piece I used to make this part. They are posed in front of the barrel with the dovetail already cut.

     There are two ways I could have created this dovetail front sight.  The easy way would be to simply make a flat piece of steel or brass.  The thickness of the material should match the depth of the dovetail.  The two ends of the steel can be filed to a forty-five degree angle to create a piece that will fit into the dovetail.  The front sight blade can then be made and soldered to the filler of the dovetail.

     The other way is to take a larger block of steel or brass and to use a mill to cut the recesses to fit the block into the dovetail and then remove the material from both sides of the sight blade.  This design allows me to let the material extend above the dovetail material and make the whole assembly stronger.  This will be clearer as the project progresses.

Figure 1

     Deciding on the depth of a dovetail is important.  If the dovetail is too shallow, the sight will not hold well.  If the dovetail is too deep, there is a potential of metal failure.  Failure is more of a concern when we are dovetailing into a barrel because of the pressures involved. I tend to cut the dovetails to be shallow near the breech, but will often cut deeper toward the muzzle where the pressure should be lower and for a shorter duration.

     My rule of thumb for barrels is to measure the thickness of material and to never cut deeper than about a  third of the way through the steel during the last quarter of the barrel near the muzzle.

  

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     I began with the block of brass and coated it with layout dye.  Once the dye had dried, I took some careful measurements of the dovetail in the barrel and laid out the complimentary dovetail cuts in the blue ink on the brass. 

     It is important to lay the lines out very carefully.  Dovetails must fit precisely together and even the slightest error toward being undersize is a cause to start over.  I used a dial caliper to measure the depth of the dovetail slot in the barrel.  Mine was .045 deep. I then scribe a line in the dye .045 up from the bottom of the part.  This defines where the flats will be milled relative to the bottom of the part.

     With the flats of the dovetail identified in the dye of my brass block, I next lay out the angle of the dovetail in the layout dye.  I do the same thing on the opposite side of the block and I am careful to add just a little extra distance between the dovetail slots to allow for fitting.  Cutting them just a hair too close will result in the need to start over.

  With my layout lines drawn on the brass block, I clamped the block in the cross-slicing vice and chucked the dovetail cutter in the drill press so I could cut a proper mate to the dovetail. It is important to note that the vertical dimension is the most critical.  I always make what I call a "touch" into the material with the tool to make sure the alignment is perfect.  I then make a very shallow cut and then increase the cut until I reach my layout line.

Figure 2

     Figure 2 shows the dovetail cutter slowly working  through the brass block.  Actually, I cut the two slots and then placed the block back in the vise to take the photograph.  That explains why the alignment is not the best in the photo.

 

Figure 3

     After cutting both sides of the block with a slot to match the dovetail in the top of the barrel, I test fitted the block in the dovetail slot (figure 3) and carefully made the final adjustments using a very fine-toothed file.

 

 

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     After assuring that my block of brass can be fitted into the dovetail in the barrel, it was time to remove the material on each side of the new front blade.   I laid out the cuts by putting layout dye on the part and using dividers to scribe two lines along the top of the block to identify the sides of the sight blade.

     I secured the block of brass in the cross-sliding vice in a way that I used an end mill in the drill press to remove the excess material.  Figure 4 shows the end mill being used to cut away the excess material from the brass block.

Figure 4

     Things move fast once the material is cut away from both sides of the front sight blade.  Figure 5 shows the crude front sight as it was again fitted into the dovetail to make sure it still fits properly. 

Figure 5

     The sight is cleaned up a little from the machining operations and sanded with a power sander to provide the basic shape before being taken to the range for sighting in.  I will need to cut off the muzzle of the barrel before further testing the gun.

Figure 6

     Figure 6 shows the basic sight installed in the dovetail and ready for a trip to the range after I cut the end of the barrel off at the line scribed around the barrel.

     There is one more addition that I will make to the front sight, but I was not able to do it in time for this article.  I will drill a very small hole down through the front sight and thread it in 4-40 thread.  This will allow me to install a tiny little setscrew to hold the front sight from moving while also allowing it to be adjusted easily when I am sighting the gun in on the range.

     Join me next month when I show how to cut the end of the barrel on this Remington.  I will also make a Buckhorn rear sight for a Winchester 94 rifle.

 

Mohave Gambler

 

  

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