Cutting Sight Slots by Hand and Fitting Sights

[Herb]

Heres how I put sights on my Stonewall Creek early Lancaster, or whatever it is.  First, true up the sights.  Grind the casting gate off the bottom of the rear sight and file it flat.  File the front and rear edges of the bases clean, sharp and parallel (measure with a calipers) using a triangular file.  I got mine from Ace Hardware, and ground the teeth off one side.  Make sure the bases are wider (across the barrel) than the bottom of the slot you will cut.  Clean up the flats of the sights with files.  Locate the front sight dovetail, which I start above the nose cap.  Scratch a line across using a square.  Saw that to near depth, .055 for me.  Use a calipers and measure the width of the TOP of the sight dovetail and scribe that with the jaws behind the first cut, a little short. Saw that in.  Make an X-cut, then saw cuts across that to the same depth to make the trough.


File the trough out, using the tri-file.  Another one that works good is Brownell's Swiss Pattern Extra Narrow Pillar File, 8", No. 2 cut, 17/64 wide.  It has safe edges and you can now true up your vertical end saw cuts, measure them for even width.  Also measure for depth at all four corners.  Likely one side, or both, will get lower than the middle.  Here I use the edge of my tri-file to scrub front to rear on the floor to see the high spots.  Then diagonally, the edge cuts well.  File those marks out.  When down enough, use the tri-file (safe side down) to make the undercuts.  The trough is made the depth of the base below the blade, so the blade will end up flush on top of the barrel.

It is difficult to file that bottom angle, better to use a sharp chisel.  This will pare off steel and will make a sharp angle.  Use the file also.  When the sight will start in, look under it.  You will see daylight in the center and that the sharp edge bases of the sight are setting high.  Chisel some more and lightly file the sharp edges off the base.  When the sight is well started in, make sure it is deep enough so the blade will nearly touch the top of the barrel.  The edges tend to hold it up.  So put a piece of brass on top of the base and lightly hammer the base down into the notch.  Look for daylight under the base and under the blade.  I like a little taper to the base so it tightens up as it is fully in.  Use your calipers.

I sawed this blank out with a jeweler's saw.  I don't care much for these blanks, preferring to buy what I want it to look like.  The sight will get filed down in sighting in. This blade came loose and I had to solder it.

The rear sight I test locate so it is not exactly at the carrying balance point, though that isn't really a problem.  You can test position it for your best focus.  I located mine 8" from the breech.  Then I measured the TOP width of the sight (fore and aft) and scribed that measure across.  Allow a little short for cleaning up.  Saw it out as for the front sight.

Here I use a carbide disc in my Dremel tool for cutting most of the base out.  Just be careful of the square ends of the notch, and not to go too deep.  Clean up with files.


Rear sight in and full down.

This is a notch I like.  Now I will test the rifle for zero, filing the front sight down to raise the point of impact.  This sight job took me about 2 1/2 hours.

[Ky Ken]

Thanks  Herb!!!!!!!

[Herb]

Here are some of the tools I used.  The top .260 wide file is marked CNCO. (with an alligator symbol, I guess), number 2.  Don't know where I got it.  Then the Brownell file which I ground off so I could cut the narrow notch deeper.  Then the chisels, I use the narrow one for cutting the edge of the slot sharper and the wide one for shaving the floor or tapping into the bottom angle.

Today I tested this sight, first shots through this rifle.  My front sight is .225" high, and the center of the rear hole is .170 above the top of the barrel.  The hole is .095" in diameter.  I held the top of the front sight in the CENTER of the hole.  The group should have been low, usually the rear sight has to be about .040" higher than the top of the front sight.  Why it grouped like this I do not know. But that is how I learn things.  The 70 grain load grouped high, so I tried 60 grains, knowing that it would group lower.  Better for informal ML matches to have the group near point of aim.  If I used a heavier charge, say 90 grains of powder for deer hunting, I would probably have to make a new, taller, front sight to have that charge group about where 70 grains does.  But first I would test the 90 grains to see where it hit!

[bluenoser]

Herb,

  Those look like plain old Stanley butt chisels for woodworking.  How well do they stand up to metal work?  I never would have considered using woodworking chisels for this type of work, but may have to give it a try.  If I do, I think I might start with one of my junk box chisels   

Thanks for the post
Laurie

[Herb]

Yes, they are Stanley wood chisels.  They cut steel good, the light cuts I make.  There are sight slot chisels, but I don't have one.

[Herb]

I fitted a new taller sight (file the sight, not the notch) to lower the point of impact.  This is a sight I like, all cast steel, .295" high.  Order number 35009 from Muzzle Loader Builders Supply.  It is .065" taller than the first sight, which lowers the muzzle and therefore the group.

I shot today in 94 degree heat to check the sight and the effect of holding the rifle at different places on the front rest.  There is photo distortion here, there is only about 1/4" cast off in the stock.  The photo makes it look crooked.
I shot the same as last time, front rod pipe resting on the cradle.  Next group was with  the rifle rested behind the entry pipe (it shot lower), but my powder measure slipped.  Discovered that after the first shot on the third target and reset the measure at 70 grains.  This was a new can of powder, too, maybe slightly slower.  I used a mid rod pipe rest on this target.  Bottom center target was with 80 grains of Goex 2F and the same mid rod pipe rest.  Don't know why shot #3 was high, but I found one patch that was badly holed, probably this one.  I can tap the front sight slightly to center the group laterally, but will not file the sight down until I decide what powder charge I want to shoot.

[Herb]

This is a composite of the four groups I shot, with three different rest positions on the forend (to see what difference that would make), and 70 and 80 grain charges.  They were expected to shoot to different points of impact.  They average about one inch left.

From this chart, a 32 inch sight radius (this rifle) and a one inch sight correction shows that I needed to tap one sight .019" over to center the group.  To move center right, tap rear sight right or front sight left.  Also, I decided to shoot 80 grains so I filed the front sight down .035" to raise the group two inches.  Then I removed the front sight to reshape it and the rear to draw file the barrel.  I tapped them back about centered, but not zeroed.  I need to take them off again to brown the parts.

On today's test, they were not zeroed laterally.  Today I used a cleaning patch dampened with my cleaning solution on the jag as I seated each ball, and cleaned the bore well after each group.  Notice from target 4 of 7/13 (center bottom) to the same load on the lower left, the velocity is 51 fps lower, apparently as a result of wiping the bore.  The 120 grain target on lower right, my chrono screens were not lined up correctly first shot  and the proof channel didn't read, so a 4 shot mean.

I then shot at 100 yards, first 3 groups with the blade at top of the rear sight hole, to raise the impact.  I can't see the top of the sight sharply, hence large groups.

On the right side group, I tapped the front sight left to center the group and aimed with the post in the center of the rear hole, as at 50 yards.  My cheek took a battering from the 120 grain loads, and I held my face away from the stock for the last (20th!) 120 grain load.  That shot hit about 6 1/2" left.  But I proved to me that this sight works.

Notice that with a clean bore, four of the five groups had the first shot quite a bit slower.  The velocities with 70, 80 and 120 grains of Goex 2F agree very closely with Lymans Black Powder Handbook and Loading Manual, volume 2, page 210, even though I have a 42" barrel and they used a 32" barrel. The three, 5-shot groups with 120 grains averaged 1995, 1976 and 2010 fps, but that is how things  go.  I don't know why two shots were so fast.

[Herb]

I see I made a mistake.  That was only the 15th shot with 120 grains that was too much for my cheek. 

[Herb]

Lyman's Black Powder Handbook (first edition, 1992) has external ballistic charts, showing the bullet path through the air.  The 2nd edition (2001) does not have this data.  Here is the path for a .495 roundball at 2000 fps (.490 is the same):
50 yards was zero.  75 yards, -.91".  100 yards, -3.11"
My zero (8/1, target 2) was 1.7" high at 50 yards.  Relatively, this added 1.5 times that amount at 75 yards, or 2.55", and twice that at 100 yards, or 3.4".  Adjusting Lyman's trajectory with this path, my trajectory was 1.7" high at 50 yards, 2.55" minus .91" or 1.64" high at 75, and 3.4" minus 3.11" or plus .29" at 100 yards.  My five shots on the right side average .33" high, which is just sheer dumb luck.  It was just chance that I tapped the front sight enough by guess for this zero, and I did not know where that group would center. Nobody should think I did this by calculation.  But this shows how high velocity and proper sighting can flatten the trajectory, at least out to 100 yards.  Ain't it fun?

[David R. Pennington]

I can definitly see potential on that round notch sight. Looks like I'm going to be cutting some new sights, I want to try it.

[Jim Kibler]

If you choose to form the dovetail notch with a chisel rather than a file, I would suggest using an ordinary cold chisel with the cutting angle reduced slightly.  Metal is upset, rather than removed when using a cold chisel for this operation.  I've seen specialized tools, but in my opinion there is no need for such a thing.  The cold chisel is simple to use and produces good results.

[Southron]

How to permanently affix your front sight:

1. Flip sight upside down and drill shallow hole in underside of it

2. Heat up and allow silver solder to flow into the hole, filling it.

3. Allow sight to cool, then file off any excess silver solder so top of silver solder in hole is flush with rest of the bottom of the sight.

4. Install sight, drift sight left or right to correct windage.

5. When sighting-in your rifle, keep in mind the word: "FORS" Which stands for Front (sight) Opposite-Rear (sight) the Same to correct for windage.

6 When rifle is sighted-in, just hit the base of the front sight with propane torch. silver solder in hole will melt-flowing down into dovetail to "permanently" affix front sight in place (or until you hit it again with the torch.)

I learned this trick from another shooter years ago and it works! Try it, you will like it-especially if there is a little "slop" in your dovetail cut.

[PIKELAKE]

Southron, that is a good idea, thanks!.....JZ

[flehto]

There's usually 6 dovetails per bbl ….4 bbl lugs, a rear sight and the front sight. When doing the bbl lugs and after the .035 deep slot is done. a dovetail chisel is used to bring the dovetail to a slight press fit w/  the bbl lug which is then inserted and the raised steel from using the chisel is peened down for a very tight fit and the surrounding area is filed flush w/ the bbl. When the chisel is used, the bottom of the slot has a tendency to rise so a file is used too flatten the corners of the slot underneath the angle.  To eliminate corner interference, I file a very small radius on the lower  corners of the bbl lugs and both sights.

The dovetail for the rear sight is done the same as was done for the bbl lugs....w/ one exception....the rear sight is fitted using a file and  the raised metal is filed into  moldings  which increase the effective depth of the dovetail to .06-.07  { the original slot was .035 deep from the bbl surface}. Again the bottom of the slot will rise when the chisel is used, so this must be flattened otherwise "daylight" will be seen under the sight.

W/ the front sight, the chisel  isn't  used...it's all done w/ a file . I make the front sight dovetail a little  deeper than .035 used for the other dovetails..... .045-.050  depending on the sight. On a swamped bbl as w/ a straight bbl,  the bottom of the slot must be parallel to the top flat of the bbl and the bottom of the blade should contact the bbl both fore and aft of the dovetail......Fred

The dovetail chisel I use has a thickness of thin cardboard placed  below the striking shoulder to protect the bbl.....Fred

[AZshot]

I was glad to see this post, to help with my next task on the Gillespie - sighting in.  Don made my rifle with a tall front, so I can file it down.  But if windage is off (seems to be, maybe 1 minute, after two outings) I was thinking of adjusting by filing just one side of the rear sight notch.  It's awfully tiny for my eyes anyway, I figure I can kill two birds with one stone.  Anyone every do it that way?

[Herb]

Yes,  I sometimes file the notch to move it to the side as I open it.