Best way to cut a notch in a rear sight

[bones92]

I know it sounds simple, and I apologize for such a mundane question...

I need to deepen the notch in a rear sight. I like a narrow, deep rectangular notch.  It helps me not only center the front sight blade, but it seems to help me replicate elevation consistently.

Is a hacksaw blade the best tool?  I have a Dremel with various metal cutting attachments.  My concern is to make the notch perfectly vertical and in line with the barrel.

I considered chucking the rear sight in my vise, and using a block with one hand to act as a guide for a hacksaw.   Or lock the sight in the vise and carefully align a Dremel cutter?

Appreciate any guidance...

[rich pierce]

I use a slitting file. I suppose a very find toothed hacksaw blade would work but not as clean as a slitting file.

[Daryl]

Depending on the width you need, 2 fine-tooth hacksaw blades taped side by side will make wider notch. Finish with Swiss needle files.

[bones92]

What's an ideal size for slitting file?  I like a narrow and nicely squared notch.

[45-110]

needle files......everyone should have a set or 2.  a Grobet set has what you need to modify a sight notch.

[smart dog]

Hi Bones,
It is hard for us to advise you about width of the notch because that is purely your preference. A flat needle file will typically cut a notch about 1/32-3/64" wide.  There are thinner files called "escapement" files that can cut as thin as 1 mm. There are also screw slot cutting files that are also very thin. Escapement files can be purchased from www.riogrande.com.  Screw slot files can be purchased from www.brownells.com.

dave

[Scota4570]

I like those sights with a wide front sight.  You can get a slight pinhole effect.  You will want it as close to you eye as allowed.  For NMLRA that is 6" form the plug.   

I have cut very thin notches-slots  with Dremil cut off wheels.  I run the disk and arbor in the milling machine drill chuck.  I put the barrel with sight in the table vice.  The sight is oriented to face me (barrel turned 90* from the shooting orientation).  The disk is fed in very slowly from the side. 

I have also done it, less neatly, with 32 TPI hack saw blades with the set ground off. 

[BOB HILL]

I've always used a very small hacksaw with the set ground off the teeth. 
Bob

[Mark Elliott]

I use specialized sight files that I got from Brownells.   

[Dennis Glazener]

I use a small flat file that came with a cheap set of five from Lowes. I have a couple sets of nice Swiss needle files but the off brand from Lowes works so well that is my preference.
Dennis

[bones92]

Seems like I need to invest in a set of needle files!

I suppose I could carefully lock the rear sight into my vise and perhaps use a short piece of trim wood as a guide to keep the proper orientation.   I just want to make sure the notch is straight (i.e. plumb vertical and cut in line with the barrel axis).

[Flint62Smoothie]

I cut the notch so that when looking down at it from above, the slot is wider towards the muzzle than the blade of the sight facing the shooter’s eye. This allows in more light and visually creates a sharper notch.

I too use a slotting file and needle files, of which I have 3 sets. I find each set has 1 or 2 in design/shape far superior to those in the other sets, even though of the alleged ‘same shape’.

[Marcruger]

The advantage to using a fine file is that you can go slow and continually check your work.  Prevents getting off path.  Just a thought. 

[Scota4570]

I just measured my match rifle.   The slit in my rear sight  is 0.026" wide.  I am not aware of any file that thin.  The rear sight is 6 1/2" from the rear of the 36" barrel.  The front sight is 0.095".  The sight picture leaves a narrow band of light on each side of the front sight when you align it right. 

[P.W.Berkuta]

I have a Swiss needle file that is diamond shaped (two vees - V - fat in the middle and pointed at the ends). I use it to cut a Vee notch in the rear sight. I've had it for MANY years and don't remember where I got it. I use it only for gun sight work.
Screwhead notch files are around but expensive. <https://www.gesswein.com/p-9827-screwhead-file-with-tang.aspx>
 
"High quality steel file with smooth sides to cut only on the edge. Will not widen the slot as it deepens."
Used for cleaning up marred slots on hard to replace screws or for filing .022" slots in new small screws.
Overall length: 4-1/2"
Cut length: 2-7/8"
25/64" wide x 0.022" thick
Available in cuts 2, 4, 6, and 8.

[D. Taylor Sapergia]

Years ago, when our eyes were better, Daryl and I would use a hunting knife and a hammer to cut the rear sight "V".  It was always perfect, but very narrow.  Now-a-days, I use a diamond shaped file with four cutting surfaces, made for sharpening Japanese dozuki saws.  The web of steel for the sight slot is very very thin, being milled out from the front with a ball end mill.

[Tim Crosby]

 Kind of like Taylor, I use a very small brad, .040?  held by pliers over the cut out and tap it with a hammer. Makes a shallow "U" but has worked for me, guess it's what you get used to. Not sure where that came form.

  Tim C.

[bgf]

A worn out hacksaw blade gives me a narrow, nearly perfect u shaped slot.  Even most needle files are too wide unless you use a wide front sight, for me at least.

[M. E. Pering]

I use a jeweler's saw with my heaviest blade, and then clean it up with fine sandpapers.

[rfd]

file only, and in my case a nut slotting file (for fretted instruments) which has a "U" shaped cutting edge.  as a luthier, i have them in all sizes, and like cutting nuts, start small (.010") and progressively work larger 'til the correct width is desired, then deepen as need be.

[Leatherbark]

Hammer a section of hacksaw blade on an anvil to remove the set (or grind it).

Bob

[Daryl]

I well remember making notches with a knife and a hammer. Tks for the long-ago memories, Taylor. LOL - yeah - they made very fine notches.

I have a wide, V-shaped file that is about perfect for a wide shallow V, wide part, side to side.

[thecapgunkid]

As I get older faster  I find I have to get persnickety with my sights.  I set the rear sight by putting a spot of rubber cement on the bottom so it won't slide off the barrel.  Then I put 'er up and shoulder the gun.  I'll move the sight a little until it is clear, pointing the gun out the back window and standing away from the wall.

The rear sight forms a bowl; and then I give it a notch to the depth of the teeth  of an off the shelf AMERICAN made hack blade..

Then I stop for coffee and a  St. Joseph's Prayer because he is the Patron of workers and I am just a goof ball prone to impatience.  Besides, I am a shoemaker and St. Crispus/Crispin are not on record as helping with flintlocks

So, now I have my rear sight in position.   Other guys can cut teeny tiny notches, whereas some of us older folks need to get Kibler to invent a classic looking and otherwise anonymous looking laser range finder sight set.

In my case, the hack blade will accommodate an 8X32 lock bolt that I cut below the threads and about a quarter of an inch above where they stop AFTER tightly screwing it into a base I  cut, dovetailed, drilled and tapped out of  a piece of scrap.   More rubber cement and it gets placed near the muzzle until it fills the slot of the rear sight.

It is God Awful ugly, HOWEVER...

Nobody taking  a gun I flip   has complained and the last gun I made put three of four rounds touching each other at the five of an orange bull in a Shoot n' C at about thirty yards.  Standing backwards...with a mirror...( Just kidding.  I have to glue myself to the bench when sighting)

I consider this  sacrilegious, however can accept it because I am a Cordwainer ( shoemaker) and not a rifle maker.  If I gotta adjust my shoes because most of us are getting older, then I can see the need to adjust gun sights.

If there's anything at all of value in this diatribe, it's that your sight set has to fit your eyes' perceptions, not some universal cookie cutter script.

Don't shoot yore eye out, kid

The Capgun Kid