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Author Topic: .308/8mm, need input  (Read 516 times)

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Offline blackpowderbill

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.308/8mm, need input
« on: August 02, 2008, 08:54:30 AM »
I am looking for advice. I have a 2a rifle that I am setting to be my lead bullet rifle. One of the things I am thinking of doing is to lengthen the neck portion of the chamber to 57mm, leaving the rest of the chamber untouched. Next I would take 8mm Mauser cases and run them through a .308 sizing die. and trim them to 57mm. Here is my rationale. When I load lead bullets (173gr) with the GC flush to the base of the neck two grease grooves stay exposed at the case mouth. In a hunting situation this is a dirt and grit magnet. With the "long necked" .308 however the grooves are covered and the neck terminates at the crimp groove.
Does this make any sense to anyone?
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Offline bluebayou

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Re: .308/8mm, need input
« Reply #1 on: August 05, 2008, 10:45:34 AM »
My first thought is that you should change bullet molds. 

Unless you have a reamer that would make the leade of the chamber longer, then the cost of having it done would probably be more than having Lee (or whoever) to make you a mold.

http://www.leeprecision.com/html/catalog/custom.html
http://www.leeprecision.com/cgi-data/instruct/Mold%20Design%20Assistance.pdf

It is a cool idea, but it seems like a custom mold would be an easier solution.

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Offline trotterlg

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Re: .308/8mm, need input
« Reply #2 on: August 05, 2008, 01:58:49 PM »
I would cast your chamber and find a reamer exactly your neck size or a half thousanths larger.  It would be easy to grind the reamer for a pilot and make a pilot to fit the chamber to support the back end of the reamer, then cut the neck to whatever length you like by hand.  Then a normal throater would make the lands start any place you want them to.  Should be a fairly easy task.  Larry
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Offline blackpowderbill

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Re: .308/8mm, need input
« Reply #3 on: August 09, 2008, 09:44:46 AM »
Thanks. I did a chamber cast the other day, the lead area shows no erosion so I believe there are the makings of a decent rifle. Yesterday at the range it  grouped "moderately ok" (4moa) with a 173gr GC WW bullet over 14 gr of Unique. Still the average size of groups fired with jacketed bullets is about half of what I got with lead bullets. I think it may be that my bullets are too small, I have sized them to .308. I am going to get a .311 sizer and try that.
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