My 2nd Krag

[ssgross]

figured out it's the bolt sleeve that is all sticky. Bolt goes in by itself, locks with cartridge smooth as silk. Even with the main spring, cocking piece, and firing pin removed, the thing is still tough to open and close. I think I need to lap the groove on the bolt where the sleeve rides, and the cam surface + cocking piece, and the inner surface of the bolt where the sleeve rotates. Enough for one day. Does anyone know if there was an armorer's manual? The one for the 1903 describing how to fit/lap a bolt was invaluable.

[butlersrangers]

The front edge of your bolt-face 'flange' may be making contact with the barrel's breech area.

'Flange' contact would create resistance and stickiness to rotating a stripped bolt fully closed (or opening it), even on an empty chamber.

[ssgross]

The front edge of your bolt-face 'flange' may be making contact with the barrel's breech area.

I thought about that, but wouldn't it still be sticky with the bolt disassembled? It is smooth as butter with the sleeve and everything else stripped off.

[ssgross]

'Flange' contact

as soon as I got home, I got the layout fluid out and checked all the surfaces. The flange does not contact the breech. The front lug has contact across the entire length of its surface, but only about halfway down from the outer circumference. The back of the rib (2nd lug) looks tight against the receiver, but no contact. The front of the bolt handle does not conact at all. All seems pretty well perfect then...except the male part of the sleeve does not rotate very freely, even when well greased. It's finish is a little rough with age and can be brightened up. a strip of 400 grit emery cloth shoe-shine fashion all around to knock all the rough off, followed by a bit of fine lapping compound with a few drops of kroil while rotating it in the bolt sleeve should do the trick. After that, a bit of lapping compound on the cocking-piece side of the cam, and just a bit to get 80% plus on the main lug should make all perfect. I don't think I need to lap where the handle root cams against the rear of the receiver. handle is mirror bright, and the receiver nice-n-smooth after bluing.

[ssgross]

So I learned on my own how to fit a NOS Krag Bolt and NOS extractor by experiment, trial and error. Tip of the day...no matter what happens, don't go get all frustrated and start lapping to death, and don't even think about pulling out the dremmel or stones and grinding away at the cams hoping it will work. patience.
1) Immediately obvious, the pivot pin for the extractor was not dished to fit the contour, which accounted for the majority of the stickiness and why it was hard to insert the collar into the bolt. Half round needle file fixed that.
2) bolt is very hard to remove. Compare to my original krag which the extractor pivots without much force. it's not loose - won't pivot with gravity, but any finger touch will pivot. Polish the pin on the new one - spin it in the drill and hold some emery paper for a few seconds. Now the bolt comes in and out just as easy.
3) The rear cam on the receiver was perfectly smooth, and the NOS bolt bright and shiny at the contact point (and everywhere else!), so I did not lap the rear cam surface. On a parkerized receiver, lapping this can do wonders.
4) Lapped maybe 2 dozen turns of the cocking piece cam. Perfect.
5) Lap the front lug while my daughter pushing a case rearward with a cleaning rod. Wasn't much to do as noted before, contact now across it's entire length and 2/3 of the way down. A family that laps bolt lugs together, stays together among other things.

Now my troubles started. Opening the bolt, all goes well and smooth until about 75% of the turn, then hits a brick wall and takes a lot of force to open - this was happening before too, but now it's more pronounced since the first part is so buttery smooth. The confusing part...put this new bolt, fully assembled, in my original krag and the pull is buttery smooth...cocks open with one finger. Hmmm. A lot of layout fluid, and comparing dimensions, scratching my head and I couldn't figure it out. So I completely disassembled the bolt and went part by part.
1) put just the bolt in...no indication of binding no matter what direction I apply force in while opening. Do NOT continue to lap surfaces hoping it will get better. It won't...especially since it works fine in another rifle.
2) put just the collar on/in - no firing control. Wammo it started binding again in the same place. The male end is sticky inside the bolt. Could this be it? lightly polish the surfaces. No change.
3) So I took the extractor off, left the collar on, and guess what, perfectly smooth turn all the way.
4) layout fluid on the extractor tip showed it was wedging into the extractor groove on the barrel. The wall in the turn is the rear cam pulling the extractor out of the slot. A micrometer showed the tip about 3 thous. wider than my original Krag Bolt. I stoned both sides down until there wasn't anymore contact. Now all is perfect.

Lastly, I painted an unfired round with layout fluid. It chambered fine as expected, but on extracting showed was binding at the web (base), and the shoulder was bumping. In pic above, just a hair stopping the bolt from fully closing on the go gauge. I went ahead and finish reamed, just couple turns at a time, until the there wasn't any more noticeable shoulder contact in the chamber - the rimmed portion of the reamer never touched the chamber mouth.

[butlersrangers]

What make of Brass is your 'test round'? Is it a factory load or a reload?

Have you tried a different assembled Bolt in this project re-barreled Krag?

(This thread has gotten rather long, covering many subjects, and I can't remember all the twists and turns).

[butlersrangers]

FWIW: On reviewing much of this thread. I believe it is possible, the 'extractor-notch' of the OP's Criterion barrel may be interfering a bit with the 'claw' of the extractor.

Metal interfering with the free movement of the extractor 'claw', (at sides, tip, and bevel), can impede the 'claw' from rising and snapping-over the beveled cartridge rim. It can add roughness and resistance to the bolt smoothly moving completely forward and closing normally.

The front part of the Criterion barrel's extractor notch does not appear to be square, especially, when compared to an original Krag barrel. (There may also be minor differences in the machined angle of the notch).
A little judicious (small) file work would likely correct the fit and function.

It is actually a bit of a marvel, how the Krag extractor is designed to move and work.


Attachment 119211Attachment 119212Attachment 119213Attachment 119214Attachment 119215Attachment 119216

[ssgross]

What make of Brass is your 'test round'? Is it a factory load or a reload?

Winchester brass - new brass but hand loads. extraction was fine.

Have you tried a different assembled Bolt in this project re-barreled Krag?

The assembled bolt on my other krag was working fine in both rifles. Micrometer showed the widths of the extractor tips were different, the new one being 3 or 4 thou. wider. Curiously, the old extractor fit the new criterion barrel just fine, and the new extractor fit in the old barrel just fine. Little stoning did the trick and all is perfect now. I dunno how I would have diagnosed the problem without having the other rifle.

(This thread has gotten rather long, covering many subjects, and I can't remember all the twists and turns).

It's been a big project! But thanks for following. I need to blue the barrel bands, rear sight, and odd bits, clean up some screw heads, then go get my stock.

I believe it is possible, the 'extractor-notch' of the OP's Criterion barrel may be interfering a bit with the 'claw' of the extractor.
Metal interfering with the free movement of the extractor 'claw', (at sides, tip, and bevel), can impede the 'claw' from rising and snapping-over the beveled cartridge rim. It can add roughness and resistance to the bolt smoothly moving completely forward and closing normally.

that was exactly it! Although I guess I was longer winded Given it's size difference to the old extractor, I chose to stone down the extractor sides rather than take the barrel off and work the cut. My witness marks are dead on and looking inside the groove may be a couple thous. off from perfect with the receiver's groove. All is well that ends well.

[ssgross]

Trigger is very well explained in Hudson's "Modern Rifle Shooting from the American Perspective". First published in 1903, it is in the public domain and a pdf can be downloaded for free. Page 30 starts the discussion of cleaning up the Krag trigger - very thorough. Trigger is next on my list while I wait on my stock.
https://books.googleusercontent.com/...nQn1mDUPOvU1XE

[ssgross]

Wouldn't ya know, I went to put the front sight blade in, and...it didn't go so well. The new production base from SSfirearms is too narrow for the new blade they sell. I put one of their blades on my original krag and it was tight, but went right down to the bottom with a couple light peck-taps with a brass punch. Well this one got stuck not halfway in...and after a few dozen taps trying to get it to go, then a few hundred trying trying to get it backed out, the whole base popped right off. Looking at the surfaces, my tinning+soldering job was great. It was holding across the entire surface. So, I had to get a new base and blade, solder it on, then re-blue the barrel.
I used the Mark Lee's express blue. It darkened my receiver! very happy with the color...but the end of the barrel I was trying to blend in turned out a bronze/copper color. I don't think the barrel was hot enough when I did the first coat. So, I sanded the whole barrel back to white and gave it another go...heating the barrel with a torch until it was just too hot hold my nitrile-gloved hand against for more than a second. Perfect results!

I then finished all my small parts. FWIW, I despise using steam to rust-blue parts. I get mottled results no matter what. they refuse to blend even after 20 coats. boiling water worked every time.

I picked up my stock last weekend too. I think I'll start a new thread just for the stock fitting.