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Krag material and heat treatment

Posted: Wed Jun 13, 2018 9:53 am
by Marlene
I know some of y’all read books.

Anybody got a source for information on materials and heat treatment of US Krag bolts and receivers? I’m trying to figure if I have to re-treat after removing material from the locking faces.

US Krag bolts were fitted with only the primary locking lug on the bolt in contact with the receiver. Norwegian Krags had both the front bolt lug and the lug on the side of the bolt body in contact. I’d like to re-fit the bolt in an action I have to the Norwegian style, but I don’t know if I can just lap it back the 0.010” it needs without re-hardening. Some stuff was through hardened and some was surface carburized.

I can interpret from description of steel types, but I’ve got no text that gives me that much. If you know of a source, I’d love to hear about it.

Re: Krag material and heat treatment

Posted: Wed Jun 13, 2018 10:26 am
by offensivename
I did a quick skim of the section of Joe Pryor's "The American Krag Rifle and Carbine" not 100% sure what I'm looking for but I found these two things that may be what you're looking for:

The bolt face was case-hardened hardened using potassium cyanide.

and:

The bolt body was case-hardened in oil then polished bright.

If thats not what you're looking for I can try searching around some more, I just skimmed the section on the bolt till I found something about hardening

Re: Krag material and heat treatment

Posted: Wed Jun 13, 2018 10:35 am
by Marlene
That’s getting close to it!

Anything about steel the bolt was made of? The full paragraph of those sentences would be awesome.

Similar stuff about the receivers would also be excellent. They may also be referred to as “actions” depending on the date of the book and the background of the writer.

Re: Krag material and heat treatment

Posted: Wed Jun 13, 2018 10:58 am
by offensivename
The Type 1 bolt body had a full-width guide rib (0.388 inch) for its entire length, see Figure ure 2-109 (arrow 1). The gas vent hole was 0.110 inch in diameter and located 0.590 inch behind the bolt face. The bolt face was case-hardened hardened using potassium cyanide. The flat beneath the bolt handle was 0.840 inch long. A square securing stud was riveted to the right side of the barrel on the bolt sleeve that entered a matching slot in the back of the bolt body.

The bolt body was case-hardened in oil and then polished bright. The Type 1 bolt body was numbered to the receiver from circa #s 31 to 400 with Arabic numerals 0.08 inch high.

There aren't any references to steel types in the receiver proper, just in references to the sear:

Four types of sears were used during ing Krag production. The Type 1 sear was made of high-carbon steel from the start of production to circa serial #20,000. The Type 2 sear was made from low-carbon steel and case-hardened in oil at circa serial #22,500.

Also a reference to the steel type of the cocking knob:
The Type 2 cocking piece/firing pin assembly was also used on the Model 1892. It was identical to the Type 1 but was made of high carbon steel starting at circa serial #16,000.

Re: Krag material and heat treatment

Posted: Wed Jun 13, 2018 12:14 pm
by Marlene
Thanks!

Re: Krag material and heat treatment

Posted: Wed Jun 13, 2018 5:56 pm
by lurker
just saw this. i have brophy's 1985 The Kag Rifle if you need me to look something up. a quick scan fails to reveal anything relevant.

Re: Krag material and heat treatment

Posted: Wed Jun 13, 2018 7:08 pm
by Marlene
lurker wrote: Wed Jun 13, 2018 5:56 pm just saw this. i have brophy's 1985 The Kag Rifle if you need me to look something up. a quick scan fails to reveal anything relevant.
Is there an index?

Re: Krag material and heat treatment

Posted: Wed Jun 13, 2018 8:19 pm
by lurker
affirmative, nothing listed re heat treatment. why don't i just send you the book? i need to get rid of some of this... stuff ayway.

Re: Krag material and heat treatment

Posted: Wed Jun 13, 2018 8:53 pm
by Marlene
I mean I won’t say no to your very generous gift. Can I offer you a bedraggled McKeever pouch to go with yours? Needs sewing and leather cleaning/conditioning but it’s the real thing and it’s there.

Re: Krag material and heat treatment

Posted: Wed Jun 13, 2018 9:05 pm
by lurker
good. may take a couple of days to get it in the mail.

Re: Krag material and heat treatment

Posted: Wed Jun 13, 2018 9:09 pm
by Marlene
Thank you!

Re: Krag material and heat treatment

Posted: Wed Jun 13, 2018 9:12 pm
by lurker
i should have declined the mckeever box, as it fails the "get rid of this crap" test, but what can i say, i'm weak.

Re: Krag material and heat treatment

Posted: Wed Jun 13, 2018 9:38 pm
by Marlene
Weakness is a virtue.

Re: Krag material and heat treatment

Posted: Thu Jun 14, 2018 8:00 am
by lurker
and sometimes virtue is a weakness

Re: Krag material and heat treatment

Posted: Thu Jun 14, 2018 9:25 am
by shinzen
Not sure if this helps or not, but it mentions a lengthy case hardening for the bolt as well, to a considerable depth, but that it was "likely a different steel than the receiver", which was Springfield Class C- same used in early 1903's. From Bolt Action Rifles by Frank De Haas

https://books.google.com/books?id=tuVUM ... nt&f=false

Re: Krag material and heat treatment

Posted: Thu Jun 14, 2018 10:51 am
by Marlene
Excellent!