install Krag rear sight

[Battis]

I'm restoring an 1896 Krag 30-40 carbine that had been sporterized. The rear sight had been replaced - the screw mounting holes in the barrel had been filled in. I have a proper sight and screws that I want to install (the sight holes match perfectly with the filled in mounting holes). Apparently there are two gunsmiths in my area - one is 20 miles north, the other 30 miles south. Neither will return a call. I'm not a machinist, though I do have a Sawzall (kidding). I do have a drill press.
Anyways, I think I can drill and tap new holes. I plan on practicing alot on a pipe or whatever.
The best solution would be to back out whatever is filling the holes. It's too hard to be solder so I'm guessing they are screws that had been filed down.
Any suggestions, tips, warnings, etc?

I won't touch the barrel until I've researched and practice enough to know that I can do it without messing it up.

[gnoahhh]

It's a bit tricky, but here goes. I did it by caaaaaarefully centerpunching the screws (or whatever is filling your holes)- first with a tiny sharp scribe to make doubly sure I was centered (best done under magnification of some sort), then enlarged with a larger centerpunch I ground to a thin sharp point. I then utilized a V-block by clamping it in place dead center under the drill bit, and then placed the barrel in the V-block and slowly/carefully drilled out the filler using a bit of the proper size for the threads I was going to tap. There will probably be some residual material from the fillers left in the original threads when done, so take care with the tap.

Weren't the threads of the original Krag screws some bastard size? Do you have a tap to match them?

[Battis]

Weren't the threads of the original Krag screws some bastard size? Do you have a tap to match them?
That is a good question. The screws I have are reproductions. I'm going to measure them (I should have done that by now) and if they are an odd size, and there aren't taps available (to me, anyways), could I then use a more common screw as long as they fit through the holes in the sight?
Thanks for the info.

[Char-Gar]

The original screw and holes have an odd ball French thread and you won't be able to find any taps. These were the same screws used to attach the Trapdoor sight.

I would drill and tap to the next largest National Fine thread. You will probably have to make the screw heads smaller to fit into the rear sight, but you can do that with your drill press.

As far as locating the holes for drilling, I prefer to camp the sight in place at the proper spot, use the shank of the drill bit in the drill chuck to position slide into the hole in the base without binding. I then clamp everything down, turn the drill bit around and make a divot in the barrel through the hole. I then remove the sight base and drill as normal. With the sight held in place by one screw, I repeat for the second screw. This is slow, but there is no chance the hole will be in the wrong place or have the wrong spacing.

[Battis]

The perfect remedy would be backing out that filler and saving the threaded hole that's there, but I don't see that happening. A larger thread does makes sense - I'd be removing any of the material that was used to fill the hole.
Thanks.

[Der Gebirgsjager]

Here's a couple of disjointed thoughts for you: The fillers might be screws, but might not be. One fairly common way to fill unwanted sight holes is to tap in soft black iron wire which spreads easily to fill the hole and blues well. So dig around at it a bit with a scribe or some other hard, sharp pointed tool to ascertain how hard the filler is. Softer = easier to remove. If it turns out to be quite hard, and might be a small bolt or screw with the head filed off, then you can anneal it to something softer by hitting it with a small size oxy-acetylene torch tip briefly to heat it red hot and then let it cool. Then, once again, should it turn out to be a screw, when softened you can drill a small center hole and might be able to back it out with a tiny easy out, which they do make, but sometimes you've got to look around for them. Failing any of that working, then your best bet is (as has been stated by others) to drill out the holes to the next larger common diameter and thread size, but success will be dependent on taking great care to get the initial center punch mark and pilot hole done precisely. I have a number of old Krags that were sporterized and have restored many of them, but to be completely honest I've never had to remove a headless screw as the ones with the holes filled were usually sporterized beyond practical restoration and best left as sporters; whereas those which it was practical to restore it seems that the previous owners sometimes anticipated that happening and were kind enough to use slotted plug screws. Best wishes on your project, and please let us know how it turns out.

[Der Gebirgsjager]

Another thought--looking past the rear sight re-installation--there are several sight models. Collectors and "purists" can be so finicky about which goes on what, but in actual practice may original rear sights were replaced in service with subsequent models by smaller unit armorers, and finding "this" sight on "that" rifle is not necessarily incorrect. So this brings up the next problem you'll encounter about which hand guard to use and where to get one, and where to get the right one for your model sight. Not all sight/hand guard combinations are compatible. I've purchased several very nicely done replica hand guards from a seller on e-bay who makes 4 or 5 different models. I can't recall is name, but he seemed to be the only one offering his products on e-bay, and I think they run about $65 each, which is a whole lot better than an original part in my book--and the originals are often cracked. The seller states the model that the hand guards are for, but even with photos of the product I've sometimes had to modify the slot on the top to make one work with a particular combination. He also offers a blank hand guard that has no slot and is solid. If you're a careful enough wood worker you can custom cut the slot for your particular sight and barrel band combination, and they look great as-is on a rifle that has had the rear sight removed and a receiver peep sight installed. Anyway--something to be thinking about.

[Battis]

The closet project I've done to this is removing nipples from antique cap and ball revolvers.
Here's a pic of the rear hole - you might have to look closely.
http://i105.photobucket.com/albums/m217/pohill/2f950182-4626-4888-906b-a35240005248_zpsejo4h1qv.jpg

[country gent]

There are alot that plugged screw holes with a screw and filed them to match the part. It works and makes a clean looking job when finished. It was the practice to bottom screw in threads and cut file head off close then lightly peen end to swell it out into threads tightly, this made a tight fit that wouldnt back out as easily. Look at the plugs under magnification and you might be able to see the start of the thread and if it is a screw. I have removed alot of broken screws with a small ball peen hammer and light prick punch. Get a starting prick on the edge but not into barrel and then angle punch in direction it needs to turn and lightly tap on it working in the direction of rotation. You can ussually back these out in this manner pretty quickly and easily. On some with a radioused surface and if a litttle proud a dremil cut off wheel can be dressed thinner ( about .020 for a short distance in from edge) and a screw driver slot carefully cut to back them out. This only works if they are threaded into the holes. if pressed in or peened in then they will need to be drilled out.

[Battis]

I'll look at it under a magnifier.
I bought a repro handguard online and a repro carbine band. The handguard fits pretty well, but it needs some more fitting. I also bought a repro saddle bar and ring, a 1903 front sight and an earlier Krag rear sight that lines up with the barrel holes.

[Battis]

My lack of metal knowledge caught up to me and I can't find the answer online.
I examined the filled holes under a magnifier and for the heck of it, scratched at one
with a pointed file tip. I was able to scratch out a slot but the slot broke down when I used a screwdriver tip. The filings from the slot will stick to a magnet.
The filler seems way too soft to be a screw but the fact that it sticks to a magnet puzzles me. Is there any type of solder that will do this?

[Der Gebirgsjager]

I doubt if it's solder, as that's mostly lead and tin, but like I said earlier it could be black iron wire. It's encouraging (to me, anyway) that it's soft. if you can dig enough of it out to allow a drill bit to start, using a bit close to the diameter of the hole in a hand drill and running it verrrrry slowly you might get more out. A variable speed Dremel might give you more control, and you'll want to clamp the work in a vise so you don't need a 3rd hand. Another trick used when desperate measures are required is to put a droplet of hydrochloric acid onto the plug. It will follow the course of least resistance and work its way down between the original threads and the plug. It's best to have some of it dug out already so that the droplet doesn't just roll off. Be aware that it will remove any bluing it touches

[Battis]

You said in your earlier post that soft black iron wire was tapped into a hole - so, heating it, as with solder, is not part of that process? Which means that heating it won't help remove it, correct?

[Der Gebirgsjager]

Correct...if that is what it is. The idea is that it is softer than the barrel steel and is malleable and will somewhat form into the hole's threads preventing it from coming back out.

I had an interesting exchange of posts some time back with some knowledgeable fellows who claimed that heat would assist in the removal of a rusted in screw or bolt from a hole. My thought had always been that it would accomplish little as heat causes metal to expand, and what would seem to be needed here would be for the screw to contract. But they pointed out that by expanding the screw/bolt, which would then contract some when it cooled, it would break the rust bond. I think they had a point, and I learned something---but I've always been pretty successful in removing plugs from holes using other means including those mentioned above. The method of using a punch and tapping the top surface of the plug counter-clockwise has worked sometimes, as was suggested by country gent; but of course, sometimes things are rusted in place too badly to overcome them with just mechanical force. You just don't know about the heat until you try it.

Your plugs seem to be soft, and I think that bodes well for a happy conclusion to your problem. I think if it was on my workbench I'd try to get the top surface of the plugs down enough to start drilling, and go with center punching the plugs and then drilling a small pilot hole followed by a larger bit, or as I suggested earlier use a very sharp bit about the size of the original hole and slowly drill it out. If you've got a good eye and a steady hand you can pretty much stay within the walls of the hole and maybe salvage it. But, if worse comes to worse and you wallow the holes out you can still drill them out to a slightly larger standard size and re-tap them. Just work carefully, be patient, and I'm sure you can do the job. Of course, that's why there are gunsmiths and BMW mechanics. If a job exceeds our knowledge and ability we can always seek help---but it usually comes at a price.

[scb]

A left handed center drill, once it gets a good bite will a lot of times back a screw like you have right out. Of course you need a drill that will run in reverse. I don't think many drill presses do. I have used regular hand drills as well as milling machines to do this. If I were doing this I would gently heat the barrel immediately before hand to loosen any thread locker that might have been used.

[bob208]

I would try to locate the center of the plugs. then try a left hand drill bit. lots of times it grabs and spins out the plug. I also would use a milling machine rather then a drill press. easier to control and more stable.

[Battis]

I carved a notch in the filler but it won't hold a screwdriver tip - it's too soft. I put some heat to it in case it was solder but it's not. I'm going to drill, pick and scratch it out with a Dremel. As Der Gebirgsjager and others said, if I have to, I can tap it to the next standard size. Hopefully I can remove the filler from the threads.

[Battis]

Well, that was easy. The front hole had been fitted with a set screw whose center had been filled in, and its top covered over. After I drilled its center, I backed it out with a file.

Most likely, the rear hole (the one I had been picking at with the file) was also a covered-over (buried) set screw and what I was picking out was whatever it had been filled and covered with. It came out in pieces, not whole as the front one did.
Amazingly, the repro screws fit the holes perfectly.
Thanks for all the tips, suggestions, and info.

[bob208]

did you buy a lottery ticket ? I would with my luck running that good.

[Battis]

It was the filler in the set screw that made me think it wasn't a screw. I'm kinda glad the gunsmiths didn't call me back.

[Battis]

I'd like to remove the recoil pad and build the stock back out and attach a correct butt plate that I have.
Any woodworking suggestions for adding to the stock? I have an old, butchered 1903 stock from which I might be able to slice off a piece the size of the recoil pad.
I'm still working on the handguard and positioning the front sight.

http://i105.photobucket.com/albums/m217/pohill/cdd09793-cd45-4040-8b04-54221545d12d_zpswnsxxkx0.jpg