Archie,
My apology as I forgot to mention earlier that sometimes you have to “clean up” the sighting notch in the rear sight. If when you look through the Rear Sight Notch (RSN) and it is fuzzy or if there is not enough light showing in the notch on either side of the front sight blade when you look through and align the front and rear sights, then you should think about cleaning up the Rear Sight notch by filing a little to true it up or change it as you prefer. However, if your RSN is crisp and clear and looks good to you, then don’t worry about it.
So perhaps it is best to explain why a RSN can look hazy or something is just not right with it. If the rear of the notch that faces your eye is wider than the front of the notch, that gives you a kind of tunnel like vision. If the notch is cut dead even through its length, but is mounted a little crooked, you will see the front part of the notch on one side as you look through the notch. If you have a “Square” or “U” shaped notch and one or both sides of the notch are crooked, that can give you sighting errors for windage or errors in the way your shots impact on the target side to side. If the bottom of the notch is hazy, that is usually because the front bottom of the notch is higher than the rear bottom of the notch. Yes, I realize you don’t use the bottom of the notch when sighting, but if not formed correctly, sunlight can bounce off it on a bright day and make the sight notch look fuzzy.
Since most of us don’t have Precision Milling Machines at home, we have to resort to files to clean up an improperly shaped Rear Sight Notch so it looks crisp and clear. If you have or prefer a “V’ notch, then you need a small knife edge file and sometimes a Knife Edge Jewelers or Swiss File is just the ticket, though sometimes you need a slightly larger file. Personally, I don’t like a “V” shaped notch and prefer a notch where the sides are parallel to the sides of the Front Sight Blade. So I use a fine Flat Jewelers or Swiss File that I ground and sanded a safe edge on one edge that is placed on the bottom of the notch and a second such file that is square if the bottom of the notch is square/flat (if the bottom of the notch is rounded, then use a round Swiss file).
I learned to clean up Rear Sight Notches by having to do it on Bullseye and International Pistol Sights, but until I learned the following trick, I absolutely hated to do it. I was originally taught to file the sight notch from the rear, but that’s the hard way to do it. It is best to file on the notch from the front of the notch so you can “sneak up” to the rear edge that you look through. It does not hurt at all if the front of the notch is a little wider than the rear, so that gives you room for human error. Matter of fact, some notches are made that way. Also, because you want the front bottom of the notch even or lower than the rear bottom of the notch, it is easier to file that from the front of the sight. Now, don’t get me wrong, there are some folks who can do a great job cleaning up the sight notch from the rear, but I’ve found it is easier for more folks to do it from the front. After you get it the way you like it, use cold blue to cover the shiny metal, then oil and dry it so there is no oil slick on the surface.
While we are on the subject of filing, perhaps this is a good time to bring up filing down the front sight if the groups you shoot are hitting too low on the target. The method I will describe is not historically correct for all time periods of front sights on muzzleloading rifles, but it works. When you file the front sight blade down, you want the rear edge that you see to be perpendicular to the sides of the front sight blade. From that edge forward, it is normally best for shooting that the top of the front sight angles downward towards the muzzle, at least a little, to ensure the sight picture is good. Now it may be daunting to some folks who have never tried to file flat and at an angle at the same time, to do this. (I remember what it was like trying to file down the front sight blades on NM M14’s and M1’s when I first began doing it and it is not normally easy at first.)
Well, there is another trick you can often use on front sights for muzzleloading barrels to do this, though not all the time when the front sight is too close to the muzzle. If there is at least ¼” to 3/8” of barrel ahead of the front of the front sight blade, this will work. You need a Nicholson or Stanley 8” Handy File that you can easily get at Lowe’s, Home Depot and other hardware stores. (There is a link to show you what I mean at the end of this paragraph.) This is a nice flat file that is medium coarse on one side and fine on the other. Normally when you file the front sight blade, you will use the fine side unless it is REALLY shooting low and you have to take quite a lot off the top of the sight blade, but you finish filing it with the smooth side.
http://www.homedepot.com/p/Nicholson-8-in-Blade-Handy-File-06601/100208251You also need a piece of drill rod or something that is round and the same diameter for at least ½ inch to one inch. (Worst case scenario is you can use a small block that is of uniform thickness.) The top of the round rod when laid down flat on the barrel across the top barrel flat and ahead of the front sight blade, needs to be a little lower than the top of the front sight blade. (Same thing for the block if you have to use that.) Now lay the cutting portion of the file on top of the front sight blade near the rear end of the cutting portion and the smooth handle on top the rod. (You do NOT want the cutting portion of the file to go over the rod.) By applying gentle pressure evenly down on the file over top the rod and pushing forward maybe 3/8” to ½” at a time per file stroke, it will cut the angle going down towards the muzzle. If you are lucky, it will also cut the rear of the top of the sight blade parallel to the sides of the blade. If not, then still using gentle pressure and short strokes, put a little pressure on the side of the file where the high spot is until the top of the rear of the front sight is perpendicular to the sides of the sight.
Sorry, but that is all I can write now, but will be back for more later.
Gus