In the case of most rifles, the sight is fastened to the rifle by removing the factory upper tang screw (the screw which holds the buttstock to the gun), placing the rear sight base hole over the empty hole in the upper tang, and replacing the tang screw with the slightly longer tang screw provided with the sight. On older Winchesters, and some current arms, there is another smaller hole forward on the upper tang. It has a tang sight filler screw in it and when this filler screw is removed, it allows replacement with the second smaller tang sight mounting  screw provided to attach through the front sight base hole and into the front tang hole.

     In the case of Model 1866 and some 1873 Winchesters, there are two small holes specifically for tang sights, and the upper tang screw does not need to be removed or replaced. However, two of the smaller tang sight mounting screws are required.

     In that circumstance when there is no front mounting hole drilled by the factory, as in Models 1894 (or “94”) manufactured after W.W.II, such a hole must be drilled and tapped. That hole should be placed by a competent gunsmith making sure it is done to properly accept the Columbia Precision Tang Peep Sight. The screw provided for the front base mounting is a 3/16 - 36 NS thread and must be drilled and tapped accordingly.

     Occasionally, the upper tang sight mounting screws provided with the sight will be longer than necessary, but they can be shortened to the proper length with minimum effort.

     It is important to note that the longer upper tang screw is of different lengths and different threads depending on the various manufacturers. Some are different among different models of the same manufacturer. Be sure you state maker and model when you order your sight and that you are using the correct screws when you mount the sight.

          The Columbia Precision Tang Peep Sight is designed to fit a number of different rifles made by several manufacturers. It will fit all pre-64 Winchesters and their facsimiles. Henrys, the models 1866 and 1873 may take two small mounting screws, as there are holes in the upper tang for both mounting screws. All the other models use only one small mounting screw and a slightly longer tang screw with a slightly smaller diameter head. These small mounting screw holes are typically filled with a plug screw which must be removed. Different bases are needed for New Winchesters with thumb safeties.

          The distance between screws (both configurations) is 2.180”, center to center (O.C. or “on center”). The length of tang screw and the thread size varies from model to model and between manufacturers, so, it is important to be sure to have the correct mounting screws. When ordered for a particular make and model, screws are shipped with each sight, and the sight package is labeled. If no maker is indicated, Winchester screws are packed with the sight.

          Sharps rifles have a slightly longer distance between mounting screws (most are 2.260” and Pedersoli is 2.250”), but use two small screws. However, these are a different thread (10-28) size from Winchester, and do not interchange.

          Brownings, as well as many recent manufacture Winchesters and others, do not have the forward mounting screw hole tapped into the upper tang. Caution should be taken when drilling and tapping this hole. The proper size tap is a 3/16 - 36 NS (Brownells does not usually stock this tap. However, Field Tool Supply Company in Chicago does. Their phone is 312-541-6500, and they will ship on a credit card). We encourage that this  be done by a competent gunsmith-machinist. If you are unable to find one in your area, the gun may be shipped to Columbia, and we will mount the sight properly for a charge of $25, plus return shipping and insurance. Please call before you ship (970-686-2865).

          When mounting the sight in properly aligned holes, start both screws without tightening either one down. When both are well started, tighten them each down a little at a time until secure.

          The Columbia Precision Tang Peep Sight has a windage element which allows for adjustment side to side. However, some arms will not have a perfectly milled or aligned upper tang . When the sight is mounted, it may not align with the barrel or barrel sights. If this occurs, and the mounting is to be more or less permanent, shimming of the sight base may be necessary. Some old timers would use anything from cigarette papers to matchbook covers to raise the sight base on one side to straighten the post to the gun. Others might strike the sight with a mallet to “bend” it into position. Although paper won’t hurt anything, we suggest the mallet not be used.

          The best way to shim the sight base is to cut (ordinary scissors will work) 1/8” wide and 2” long strips of steel shim stock (.005” thick) and lay them in position under one side of the base. Generally, three such shims, one on top of another (held together with a drop of rubber cement), will solve most problems. This can be done with mounting screws loose enough to slide shims  under the side of the base, out of sight.

          The elevation post, which holds the aperture, will always have some rotation or “looseness” to it. The amount of looseness will vary from sight to sight, but it will never rotate more than about 5 degrees. This amount is not visible to the eye when using the peep, so is not a problem when shooting, and does not affect accuracy.

        
  The Winchester New Models of 1886, 1892 and 1895 all have a thumb safety on the upper tang. Columbia Precision makes a sight base especially tailored to accommodate this safety. One is slotted to allow access to the safety through the sight base (‘86). Another, (for the 1892 and 1895) is shortened and does not interfere with the safety. However, some care must be taken in drilling and tapping the front mounting screw hole, as it is not cut at the factory like pre-war Winchesters.

          The distance between screws is 2.180”, center to center (O.C. or “on center”) on the ‘86. The distance between the tang screw and mounting screw on the 1892 and 1895 is .500” O.C. The length of tang screw for the ‘86, and the thread size is the same as on the Browning 1886, no longer in production, even though the New Winchester 1886 has a pistol grip stock. The ‘92  and ‘95 screws are slightly shorter. It is important to be sure to have the correct mounting screws. When ordered for a particular make and model, screws are shipped with each sight, and the sight package is labeled. If no maker is indicated, old Winchester screws are packed with the sight.

          The proper size for the front mounting screw hole tap is a 3/16 - 36 NS. (Brownells does not usually stock this tap. However, Field Tool Supply Company in Chicago does. Their phone is 312-541-6500, and they will ship on a credit card.) We encourage that this  be done by a competent gunsmith-machinist. If you are unable to find one in your area, the gun may be shipped to Columbia, and we will mount the sight properly for a charge of $25, plus return shipping and insurance. Please call before you ship (970-686-2865).

          For the Models 1886, a hole should be drilled into the top of the upper tang using a 5/32” bit (.156”) or, preferably, the same size end mill. Then a flat bottomed tap should be used for cutting the threads. This hole should be a maximum of only .125” deep. The thumb safety is attached to the bottom of the upper tang with a screw which penetrates the tang .125” from the bottom. Although this screw hole and the front mounting screw hole are not in exactly the same place, the holes may overlap, and the screws interfere, if either is drilled too deep. The thickness of the tang at this  point is slightly more than .250”. The thumb safety mechanism should be removed before drilling and tapping the front mounting hole for the tang sight. For the Model 1892 and 1895 there is no interference with the safety (it has a shorter base) and the mounting screw hole may be drilled and tapped all the way through the upper tang. The mounting screw hole is just .500” in front of the upper tang screw, and does not interfere with the safety mechanism at all.

          When mounting the sight in properly aligned holes, start both screws without tightening either one down. When both are well started, tighten them each down a little at a time until secure.

          The Columbia Precision Tang Peep Sight has a windage element which allows for adjustment side to side. However, some arms will not have a perfectly milled or aligned upper tang . When the sight is mounted, it may not align with the barrel or barrel sights. If this occurs, and the mounting is to be more or less permanent, shimming of the sight base may be necessary. Some old timers would use anything from cigarette papers to matchbook covers to raise the sight base on one side to straighten the post to the gun. Others  might strike the sight with a mallet to “bend” it into position. Although paper won’t hurt anything, we suggest the mallet not be used.

          The best way to shim the sight base is to cut (ordinary scissors will work) 1/8” wide and 2” long strips (shorter for the ‘95) of steel shim stock (.005” thick) and lay them in position under one side of the base. Generally, three such shims, one on top of another (held together with a drop of rubber cement), will solve most problems. This can be done with mounting screws loose enough to slide shims  under the side of the base, out of sight.

          The elevation post, which holds the aperture, will always have some rotation or “looseness” to it. The amount of looseness will vary from sight to sight, but it will never rotate more than about 5 degrees. This amount is not visible to the eye when using the peep, so is not a problem when shooting, and does not affect accuracy.

     
There are no sights made by us which are specifically made for Marlins. Our sights are manufactured mostly for Winchesters and their imitators, as well as an occasional Sharps and some other single shots. Several years ago, when we first made a small run of these sights, we tried to fit all the Marlins. The variety in tang lengths, hole spacing, types and sizes of mounting screws required, as well as the irksome placing of serial numbers on the top tang by the Marlin Company, simply makes the effort uneconomical for us.

          However, since there are a lot of Marlin shooters out there, and I sympathize with their need for a quality tang sight, I made a number of blank bases - no screw holes at all. A competent gunsmith-machinist can mount one of our sights on a Marlin by positioning the sight to suit, and drilling the sight base and tapping the mounting screw holes in the upper tang, or by using existing mounting holes in the older guns.

          Please understand that there are problems with this procedure. I have no mounting screws for Marlins, so the gunsmith will have to supply his own. I can supply two small Winchester mounting screws if new holes are to be tapped anyway, and you choose to use the Winchester tap size. Also, one needs to be aware that the hammer on a Marlin, when cocked, does not allow for the tang sight base to be under it. It must be mounted far enough back not to interfere, or the base must be shortened to accomplish the same purpose.

          Now, if all this doesn’t discourage you, I will ship either the short or tall post sight you wish with a blank base, and Winchester screws, if requested. The short post sight fits the short cartridge (.44-40, .32-20, .22LR, etc.) and medium cartridge (.30-30, .25-35, etc.) guns, and mounts forward on the tang near the hammer. The tall post sight fits the long cartridge (.45-70, etc.) guns, and mounts toward the rear of the tang near the stock comb. If you are in doubt, tell me the model and caliber and I’ll ship the appropriate sight with blank base.

          I will also mount the sight properly on Marlin rifles, if you care to ship me the gun. I have mounted sights on Marlins of every sort, so it is certainly not a problem if done right. The charge for this service is $40, plus return shipping and insurance. It is not necessary to have an FFL for this service, as the gun is essentially being shipped “for repair” , and will be returned, usually within 10 days. By all means call, if you have questions, or are planning on sending a gun.