How to file down the front sight

[hhughh]

Measure the sight radius or distance between front and rear sights.

Joe,
How do you measure sight radius on a fowler (no rear sight)?

Thanks

 

[Black Hand]

Your eye is the rear sight....

 

[Wyomick]

FWIW:
Kept my buckhorn rear on my Pedersoli 54 Cal. Frontier Carbine and filed the front sight down so as to zero at 50 yds with the front sight post even with the top of notch at bottom of buckhorn rear sight for a 6 O'clock hold sight picture on the bullseye (formula is a ratio: X/L = SR/DT, all in inches; solve for X: X = Inches shooting Low x (Sight Radius in Inches/Distance to Target in Inches). Example: X = 4" low x (18" sight radius/600" to target = 4 x (0.03) = 0.12" or 1/8" to remove off front sight = No Guesswork!). Then I took a jewelers file with the file on the edge only (rounded edge) and filed the Buckhorn notch down about 1/32" - 1/16" which also widened it. Great sight picture and easy to see with old eyes, and pick up on an animal using the 6 O'Clock hold.

 

[Sun City]

Me thinks those files are called FLAT BASTARDS!! :surrender: :bow:

 

[azmntman]

:hmm: wife calls me a round bastard :rotf:

 

[Oregononeshot]

I was wondering the process for this as well. I filed down my front with a flat file but it took a long time to raise it 2 inches at 75 yards. I'm tempted to take a bench grinder to it to remove about half the front sight (that's what I calculate I need to remove to get on target) but I'll probably just use the flat file.

 

[Artificer]

I can understand how some other folks do not want to file the front sights down at the range. I always carry a homemade padded cleaning vise with me when doing such work, so I can lock the gun into the vise while filing on it at the range.

Generally the math formulae has already been given, but I must stress that while one can quickly remove metal off the front sight down CLOSE to the point given by the math, I have found too many times that because of the differences in human eyes, it often does not work completely. I suggest stopping 1/16th above the point one gets to the height determined by the formula and then filing the remainder on the range.

OK, perhaps I am mistaken, but I don’t think many or even most folks who have not had training using hand files to remove metal, will wind up with the top of the sight perpendicular to the height. So may I suggest a way to file cut the front sight so the top of the sight will wind up perpendicular to the blade or at least very close to it?

The first thing you need is a hand file and IMO the best one for it is not that expensive and can be found in most Big Box Hardware Stores. It is an 8” “Handy File” with one side having single cut teeth for fine filing and the other side has double cut teeth to remove metal faster. Stanley, Nicholson and Kobalt all make this file because it is so generally useful and all makers make them in the same shape. Below is a link to Lowes’ and theirs is made by Kobalt. https://www.lowes.com/pd/Kobalt-8-in-File/4326447

The other items you need are:

1. A pair of precision dial or digital calipers and a black magic marker. These are used to transfer the height distance from the formula to your front sight. Blacken one or both sides of the front sight with the magic marker and when the calipers are opened to the correct height, hold the calipers so the jaws don’t move and lightly drag one jaw point on the barrel and the other jaw point along the side of the sight. This will give you a line on the side of the front sight that you can see easily, so as not to file down too far.

2. Some kind of chalk to chalk the file teeth and keep filed pieces from clogging the file. Regular White Blackboard chalk is most commonly used, but any colored chalk will also work. You rub the chalk into the file teeth on either side of the file you are using.

3. Either a “file card” or one of those small hand brushes that look like tooth brushes, but the bristles are either steel or bronze. An old worn out bronze bore brush will also work. This is used to brush the chips loose as you file, then re-chalk and file some more.

4. Though breaking the sharp edge on each side of the front sight after you get the right height can be done with the Handy File, I bring small needle files to do that and also for very fine height adjustments or at least to smooth the top more near the end of filing. However, this can also be done with some sandpaper or better still Emory Cloth (sandpaper for metal) wrapped around a small flat block of wood.

5. You will also need something that is either flat on both sides or completely round and is the same or slightly higher height (or diameter in case of a rod) than the math formula tells you the front sight should be. So for example, if the formula says front sight is supposed to be 3/8” high you will need something flat a little taller than that or a rod that is also a little larger in diameter. I suggest a piece of flat stock or round stock 1/8 inch taller and that would mean ½ inch in this case. I have used square or hexagon ends of drive pin punches, round stock, or even scraps of flat stock that are a bit larger/taller than what you want to end up with.

OK, so why should these pieces be a little taller or larger in diameter in the case of round stock/rods?

The reason is you will use the flat edge or round stock to lay on the barrel top as a guide behind the front sight. The handle of the file runs on top of it while you cut the top of the front sight. This will help keep the file cutting perpendicular to the height when viewed from the rear through the rear sight AND it will also cause the file to cut the top of the front sight angling down just a tiny bit as the sight goes forward towards the muzzle. When the top of the front sight angles down toward the muzzle just a little bit, it will keep the reflected light from giving you a blurry front sight picture on sunny days.

NOTE: On many original rifles, the top of the front sight was filed so it looked like a spear point at the top, when the front sight was viewed from the rear. However, that is not what most of us are used to or want. If you do want that kind of top on the front sight, then ignore the following directions.

First blacken one or both sides of the front sight and use the pointed ends of the caliper (opened and held to the height you need) to mark one or both sides of the front sight.

Chalk the double cut side of the Handy file and file down the top somewhat close to about 1/16” higher than that line. It is a sure thing you will need to stop occasionally to brush clean an re-chalk the file to do this. Once you get down close to 1/16” above the line, stop filing and get out the flat stock or round rod that is a little taller than the scribed line.

You place and hold the flat stock or round rod across the top barrel flat maybe an inch behind the front sight. ONLY the smooth/flat handle of the file will lay on and go over the flat stock or round rod as you file further. You keep a little pressure on the handle over the flat stock or rod as you continue to file cut the top of the front sight. This will keep the file perpendicular to the top of the barrel flat as you file further. Of course it will file cut the very front of the top of the sight first and as you file more, the cut edge will extend back to the rear of the top of the front sight - at an angle going downward toward the muzzle when viewed from the side. Once you get to the rear of the top of the front sight, then stop file cutting.

At this point it is time to go back to the range and see if you cut enough metal off the front sight to raise the point of impact of the group where you want it on the target. If not, you can either use the handy file or small needle files to make the final cutting adjustments. Don’t forget to file the burr or sharp edges off the sides of the front sight.

Gus

P.S. This technique is basically how we used to file down the front sight on NM pistols. However on them, we laid the smooth flat file grip on the top of the rear sight while we filed down the front sight. That kept the top of the front sight parallel to the top of the rear sight and it also gave us the angle on top of the front sight going down from the rear of the front sight towards the front of the front sight.