32 Steps - in manufacture of U.S. Krag barrel

[butlersrangers]

This April 26, 1900, American Machinist Magazine article, by E. G. Parkhurst, describes the manufacture process used to make a Krag barrel. Although, not specifically naming the Krag or S.A., there is no doubt this 1900 article is describing the operations and steps in use at Springfield on Pratt & Whitney machines.

[butlersrangers]

It is very amazing to read about the intensive labor and operations involved in making a Krag barrel.

The complete chambering was done before a barrel was ever screwed onto a receiver. The barrel was a completely finished unit, before assembly onto an action.

(I wish the article had described barrel 'proofing'. As I understand the process, 'proofing' was done before a barrel was rifled).

[Knute1]

I posted this before, but below is a link to Scientific American, an article about a year earlier then the American Machinist article. Not as detailed as your findings above, but it may compliment it to some extent. The article starts on page 267 and continues on page 330. Also, see page 323 for a picture of a Krag tested to destruction.

https://books.google.com/books?id=y4U3AQAAMAAJ&pg=PA330&dq=krag+jorgensen+machining&hl=en&sa=X&ved=0ahUKEwj4g8DtwNnhAhVO7qwKHa0fA5YQ6AEIKDAA#v=onepage&q=krag%20jorgensen%20machining&f=false

Articles from the American Machinist and Scientific American showed up together in a period "Engineering Index" under Krag-Jorgensen for those seeking information on the subject back in the day on page 786.

https://books.google.com/books?id=U1A0AAAAMAAJ&pg=PA786&dq=krag+jorgensen+Engineering+index&hl=en&sa=X&ved=0ahUKEwjG-t2oztnhAhUS0KwKHWGXA9MQ6AEIKDAA#v=onepage&q=krag%20jorgensen%20Engineering%20index&f=false

[FredC]

I have a tough time reading in depth articles on a screen. I do a lot better with print. Just found a reference to drilling and reaming the front sight hole. Must be another 30 caliber barrel being described, not Krag. I had thought the threading was indexed to the barrel from previous discussions but these barrels are threaded first then holes are drilled for the sights. So after threading, the barrel would be screwed into a bushing with a shoulder to get it clocked or timed correctly. all barrels get screwed into the same bushing. As that bushing wears and timing gets off it could be corrected by rotating it to bring the timing back, that is assuming the machining order here is roughly the same as done on the Krag.
I think for the Krag, I would have made the dovetail machining and rear sight drilling as part of the same set up top avoid errors of moving the barrel between operations. But that is based on the way I think not necessarily the way it was done.

[FredC]

I thought the threads on my Krag barrel were lathe cut. Dragged the old barrel out and looked at it with a 7 power loop and I am not sure. Some of the marks look like conventional single point lathe turning and some look like they could be milled as described along with the figure 12 of a thread milling machine.
I thought thread milling was a later invention. Live and learn. Even if this is not the Krag operation described it is very informative as to what was being done in that time period.

[Parashooter]

. . . Just found a reference to drilling and reaming the front sight hole. Must be another 30 caliber barrel being described, not Krag. . .

I suspect the hole in question is for the blade retaining pin - drilled straight then reamed to the taper that has frustrated so many who attempt removal in the wrong direction. :-X

[FredC]

. . . Just found a reference to drilling and reaming the front sight hole. Must be another 30 caliber barrel being described, not Krag. . .

I suspect the hole in question is for the blade retaining pin - drilled straight then reamed to the taper that has frustrated so many who attempt removal in the wrong direction. :-X

If so then the mill cut and soldering the front base would have already been installed in a separate timed or clocked operation. Possible, I guess. Too, bad all the ones that worked there are dead and can not solve the puzzle.
The article did mention drilling with a sensitive drill then reaming. If the reaming was with a tapered reamer that would fit and this could be Krag barrels described. ?????
Went back and looked for a drawing of the drilling machine, not included, if it had been it might have had revealing clues.

Parashooter,
Went back and looked at the reamers and they sure look like 30/40. 1900 is probably too early to be tooling up for the 03-A3 Springfield.

[Parashooter]

Parashooter,
Went back and looked at the reamers and they sure look like 30/40. 1900 is probably too early to be tooling up for the 03-A3 Springfield.
The US Krag front sight base has a transverse hole for a tiny pin that retains the front sight blade (visible at top of attached image). What has this to do with the 03-A3?

[FredC]

Parashoooter,
I was actually agreeing with you the machinery discussed in the article is probably for the Krag. I thought they might have been tooling up in 1900 for the 03A3, but your pointing out the hole in the Krag front sight base makes it look very probable all the machinery is for Krags.

If it had been me I would have finished all that last bit of machine work (dove tail and rear sight holes) in one operation and soldered a finished base to the barrel later. They may have had a good reason for not doing it that way. Big whoopsie on my part.

[Parashooter]

. . . I thought they might have been tooling up in 1900 for the 03A3 . . .
If it had been me I would have finished all that last bit of machine work (dove tail and rear sight holes) in one operation and soldered a finished base to the barrel later. They may have had a good reason for not doing it that way. . .

That would have been a very long lead time. The 03A3 wasn't developed until 1942.

The slot and pin hole for the blade would have been liable to distortion during the brazing (not soldering) and milling of the base. Leaving these operations until later ensures the blade and pin will install properly.