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Shooting & Reloading - Mausers, Big Bores and others >> Mannlicher Discussion forum & Archive
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MikeRowe
.333 member


Reged: 23/11/11
Posts: 478
Loc: Arkansas, USA
A Steyr gets a new bolt head.
      #215423 - 25/08/12 05:08 AM

This particular Steyr 6.5mm did not have it's original bolt, as evidenced by the fired cartridge case on the left.





We can either set the barrel back a turn and recut the chamber, or make a new bolthead .010" longer. As the bolthead was a little loose and sloppy, it was elected to make a new one. Should be done in an afternoon......yeah, right.







First, a blank head is turned on the lathe, being sure to leave a collar to machine the bolthead retaining lug.



Of course, as with almost every unusual job, there's a new tool to be made. In this case a .300" X 45 degree dovetail cutter for the ejector seat. Not too bad, about 40 minutes with the lathe, and filing in the teeth, and it's ready for heat treat. And there's always plenty of stuff around here ready to make a batch to go in my furnace.



The blank is now chucked into the dividing head on the mill and dialed in to center with a test indicator. This will make indexing easy and accurate.



Most of the collar is pruned away, leaving the retaining lug to keep it in the bolt body.



The slot's cut for the firing pin, and then the extractor slot. Must remember to leave it a little narrower at the rear so the dovetail can be cut to retain the extractor.



Now I get to try out my new dovetail cutter.





That worked very nicely. The little pocket for the tip of the ejector retaining screw is next.



Back to the lathe, and using a specially ground drill bit, the firing pin hole is formed and reamed.



All polished and ready for heat treatment.



Out of the fire, repolished and final fitted to the body. Ready for testing.



And the cartridge on the right in the first photograph is the result.

An afternoon had morphed into a day (a long one)...oh well.

Edited by CptCurl (18/11/12 11:50 PM)

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lancaster
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Reged: 06/05/08
Posts: 9033
Loc: There's a lighthouse in the mi...
Re: A Steyr gets a new bolt head. [Re: MikeRowe]
      #215425 - 25/08/12 05:33 AM

looks good so far waiting for the rest

--------------------
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.
bringing civilisation to the barbarians

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MikeRowe
.333 member


Reged: 23/11/11
Posts: 478
Loc: Arkansas, USA
Re: A Steyr gets a new bolt head. [Re: lancaster]
      #215427 - 25/08/12 05:45 AM

I think it's done now - I'm not really a computer guy.

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Phillip
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Reged: 31/05/10
Posts: 174
Loc: North Carolina
Re: A Steyr gets a new bolt head. [Re: lancaster]
      #215432 - 25/08/12 05:53 AM

Wow..how much time so far? Nice looking work!

--------------------
My rule of life prescribed as an absolutely sacred rite smoking cigars and also the drinking of alcohol before, after and if need be during all meals and in the intervals between them.
-Winston Churchill


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tinker
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Reged: 12/03/05
Posts: 4835
Loc: Nevada
Re: A Steyr gets a new bolt head. [Re: Phillip]
      #215435 - 25/08/12 06:23 AM

Great little project.
Nice images and detailed explanation of your process.

Thanks for posting it!

What steel?
What were your furnace and time values for heat treat?
Do you have a hardness tester in your shop too?





Cheers
Tinker

--------------------
--Self-Appointed Colonel, DRSS--



"It IS a dangerous game, and so named for a reason, and you can't play from the keyboard. " --Some Old Texan...

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MikeRowe
.333 member


Reged: 23/11/11
Posts: 478
Loc: Arkansas, USA
Re: A Steyr gets a new bolt head. [Re: tinker]
      #215437 - 25/08/12 07:28 AM

Tinker

The steel is O1 oil hardened at 1500 degrees, and drawn at 575 degrees for 2 hours. This (for me) makes an extremely tough and durable part.

The above is what I do for this part. It works for me, and my gear. It may or may not work for anyone else, and is for information purposes only. (I have to cover my hindquarters here). There are so many variables, such as; steel batch/manufacturer; oil type, temperature and agitation technique; furnace temperature accuracy/control; scale control, and other things. You have to experiment to find what works.

As for a hardness tester, I don't have one. I do what works from experience. Rockwell numbers are a guide to get you close. And different heat treatment processes can yield the same number, but instill vastly different properties, strengthwise, in the steel.

Edited by MikeRowe (25/08/12 10:43 AM)

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CptCurlAdministrator
.450 member


Reged: 01/05/04
Posts: 5284
Loc: Fincastle, Botetourt County, V...
Re: A Steyr gets a new bolt head. [Re: MikeRowe]
      #219782 - 18/11/12 11:52 PM

Mike,

I stand in awe. Wish I had such skill.

Curl

--------------------
RoscoeStephenson.com

YOUR DOUBLE RIFLE IS YOUR BEST FRIEND.



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Caprivi
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Reged: 30/09/08
Posts: 811
Loc: America's Serengeti, Buffalo W...
Re: A Steyr gets a new bolt head. [Re: CptCurl]
      #219791 - 19/11/12 04:50 AM

Great stuff. So very glad there is craftsman hiding in there shops out there doing such fantastic work.

Is this on the bolt that is getting the Coker/Fraser handle ???

--------------------
To live life as it is handed to me from God

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MikeRowe
.333 member


Reged: 23/11/11
Posts: 478
Loc: Arkansas, USA
Re: A Steyr gets a new bolt head. [Re: Caprivi]
      #219916 - 21/11/12 06:30 AM

Yes, on one of them.

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