Converting original 1866 to center fire

[nativeshootist]

I can see why this conversion is a doozy, especially now with original part being hard to come by and expensive. have you tried cutting some brass stock?

[Four Eyes Henry]

Why don't you glue the collar in the bolt and let the firing pin ride trough it, you can even get a (return) spring between the collar and the firing pin. Some sort of not so super tight loctite (one that lets go after a little heating) should do I guess.

Just something I thought of when I saw your foto's....

[DJ]

My hesitation with a pin that slides through a fixed collar is that there isn't much holding the piston in the gun in the first place, and unthreading it from the collar removes some of that.  Once the little thin 40-to-the-inch threads in the collar are no longer in play, in the event of say, a pierced primer or case failure, there's the extractor that fits in a rounded cutout in the top of the piston (but the extractor is held by a pin only  about 1/16 of an inch in diameter).  Next stop after the extractor is the hammer (which should at least be in the forward position), and right behind that is my face.

Putting my problem-solving skills to use, I decided to try going the other direction by making a one-piece bolt face that incorporates the collar and the central firing pin--with this design there's no hole that goes through the center of the bolt.  I still need to play with the proper dimensions of the firing pin, but this at least shows promise and I think would be a little safer.

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[Cholla Hill Tirador]

 Watching this one with great interest.

 I ran across a REALLY nice '66 carbine for $4500. So tempting...

 CHT

[nativeshootist]

Hey DJ, just wondering where you're at on this conversion.

[nativeshootist]

Just checking if you're still working on this

[DJ]

Sorry for the long absence--one thing after another, then waiting on a tool (Woodruff key cutter).  My little Maximat mill and lathe had been boxed away for a dozen years while I lived other parts of my life.  Got the lathe out again about two year ago, but the mill was still in the box.  Needed to reassemble it, try to get it true (apparently not quite there), repack the gears with grease, etc.   Oddly, I just got back to it yesterday (took a day off with the kids out of school), and today have what I believe is a working prototype.  I'll try to get some photos posted to show how it is ending up.

--DJ

[DJ]

I knew I needed a round key cutter (Woodruff) to cut the quarter-moon notch in the striker, so off to Ebay.  It was easy to find a cutter to fit the diameter of the notch,  but I could not find one the right width--all were either too thin or too thick, and I didn't want to spend the $$ for a custom width.  I also didn't want to cut it twice with a thin cutter, because I was afraid it would throw in an unneeded variable.  So (and I suspect this is blasphemy to the real machinists among you) I bought a cutter that was a little too wide and used a carbide bit in the lathe to reduce its width.  I had given up on finding my vise (things can be hard to find after a dozen years) so I installed the piston/striker in a quick-change tool holder as if it had been a round boring bar.  I then turned my milling head sideways, which involved pulling the chuck off of my lathe head to make room.  Here are some photos of the cutter setup (cut already made) and the relationships of the parts.  Silly me didn't realize the quarter-moon cut is in two different diameters--interestingly the deeper cut is machine-made, but the two edges appear to have been filed on.

[DJ]

Here are a couple shots comparing an original with the conversion.  You can see the file marks on the original cutout--not sure why'd you be filing there.  Even though I didn't match the diameters correctly, it looks like it should work.

[Coal Creek Griff]

I have to tell you that I'm really impressed with your work. This is a very cool project.

CC Griff

[DJ]

I also cut the bevel on the back end of the striker--I just tried to mimic the original--I don't think tolerances are very tight on this end.

After that comes reassembly and then some more primer tests.  Based on the design, I cannot see why the Model 1866 does not have a reputation for accidental discharges and slam fires, but perhaps I'll find out.  Weirdly, a couple years ago I saw dies on Ebay for .44 Evans Short and .45 Henry Flat.  I don't have an Evans that shoots the short cartridge, but happened to know they would work with .44 Merwin Hulbert.  I also figured that "someday" I might reload a Model 1866, so got the Henry dies as well--I mean, how often do you see those for sale?  So during primer testing I also plan to start working up a cartridge.

[dusty texian]

Looking good ! Have been keeping up with your project  , anxious to see how it fires ! ,,,DT

[DJ]

Well, something always comes up.  I got the action reassembled and it all seems to work.  I had a couple of .44 cases that are .440 in diameter and short enough to fit in the chamber, so I tried them out, and the primers went off as they should, so there's progress.

[DJ]

Now I'm working on forming some brass.  The "book" diameter of a .44 Henry seems to be .446, which will take some work.  Oddly, the used .44 Henry dies (by CH-4D) I have seem to form a slightly bottlenecked case, with a base of .448 and a neck of .440.  Not sure what that is about, but it will be interesting to see.  In any event, I figure I can form and shorten .44 Russian cases, but I have broken enough dies to know that you run a risk if you try to full-length form a case from .457 (.44 Russian case head diameter) to .446 with regular sizing dies.  You need to take special steps when forming the head, and anyone who has heard that telltale "ping" of a die cracking knows what I mean.  Fortunately, last summer I made up a series of head swaging dies out of bolts to take .44 Special case heads (.457 diameter) down to form .44 Merwin, Hulbert cases (which are a straight case of .440 diameter), so if I poke around through what I've got already, I may have what I need.

Of course with every "fortunately" there is usually an accompanying "unfortunately," and today is no exception--it seems this rifle was dry-fired enough that the rimfire firing pins made dents in the end of the chamber--they're actually pretty small, but they have raised corresponding burrs on each side of chamber, at 3:00 and 9:00 o'clock that scratch the full size brass more than I'd like.  They must be fairly small--only few thousandths tall--because they don't scratch a .440 diameter case, but they are big enough to scratch a full-diameter case and interfere with seating a cartridge of .448 diameter.  I suspect they would also put some drag on the case after it is fired, which could be a problem with extraction--1866 extractors are not particularly robust.  With the geometry of the barrel and receiver, these will be a little tough to get at, but I am not interested in pulling the barrel out of the frame, so we are in a delay mode for a little bit while I hunt down my bent Swiss riffler files to see if I have something suitable to use.

Below are photos of the chamber burrs and the partially formed .44 Russian cases.  The burrs show as two little shiny areas at 9:00 and 3:00 o'clock.  The case shows several scratches, because I ran it into the chamber a few times to find the location of the burrs.  You can see that each scratch starts about a third of the way down the case, which is about the bottom of the very very slight bottleneck formed by the dies.

--DJ

[Cholla Hill Tirador]

  I'm enjoying following this.

  Regarding the problems with the chamber and pulling the barrel; I have an old '73 Winchester (1886 production) whose barrel was hopelessly pitted and needed to be lined, which of course required pulling the barrel. Even though I'm not a gunsmith, the process was dirt clod simple.
  I found that a 1" x 2" board such as one finds at a lumberyard fit the carrier mortise perfectly (I used oak). So using a center punch I indexed the barrel in a hidden area under the forearm, used a hydraulic press and two oak blocks to clamp to hold the barrel, put the 1 x 2 board through the carrier mortise, and simply screwed the frame off the barrel. It required very little effort to break the receiver free of the barrel.

   

 For a round barrel, one would need to groove a couple of oak blocks and apply a little rosins.

After John Taylor lined the barrel and returned it to me, I simply reversed the procedure screwing the receiver back onto the barrel until the indexing marks were aligned. Easy-peasy.

 I bet that once the barrel were removed, the raised areas at the rear of the chamber could be carefully worked down.

 CHT

[Mike]

Looks like rust may be causing the case marks. Do you have a bore scope. I wold use some steel wool and polishing compound and work slowly from the chamber mouth in.

[Fox Creek Kid]

You'll have to make one of these in the right diam.:

[DJ]

That is a fascinating tool--I'm going to have to figure out how it works.  I don't know if I will need it for this project, but I have a couple of Spencers that could use some help.  On account of its firing pin design, dry-firing a Spencer can raise a lump in the chamber about 1/8 of an inch wide, and deep enough to keep a case from even entering the chamber.  I would love to try ironing out the lump with such a tool.

As for my '66 conversion project, it appears that the firing pins only raised a couple of pretty small burrs.  I believe I have them cleaned off, and have the brass equation solved (although I still need to make a few cases).  I have moulds for bullets that will fit, but none of the ones I tried make a cartridge long enough to function through the action.  "Somewhere" I have one more mould I intend to try, but I need to locate it first and cast up some bullets.  I've now tried primers several times, and they consistently go off, so I think we're getting close.

--DJ

[PJ Hardtack]

I envy your machining and engineering skills! Fascinating to watch your work in progress.

[Coal Creek Griff]

I envy your machining and engineering skills! Fascinating to watch your work in progress.

I wholeheartedly concur!

CC Griff