Author Topic: Case Forming - 30-06 Gov to 8mm x 57 Mauser  (Read 2389 times)

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Offline jd?

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Case Forming - 30-06 Gov to 8mm x 57 Mauser
« on: November 21, 2014, 10:12:15 PM »
I know that many of us are shooting 8mm around here, and at least a few are reloading it also.  And somayas who aren't loading it oughta be.  Problem is that reloadable boxer primed brass can be tough to find, and if you're a tightwad like me you can't hardly bring yourself to buy a box of commercial ammo - or full priced brass.  Sooo, I've got a solution.  It's not a big secret, but I think most folks don't want to mess with it because they think it's a bigger hassle than it is.  There are a few You-Tube vids on this, but after watching a couple of them, I felt even dumber than I started out as.  Some people just shouldn't make these videos.  They did however teach me that it can be done, even by folks with very limited intelligence and organizational skills. 

Here's what we're after.  Basically the -06 case is a little bit larger in all respects except for the dimension of the case mouth.  And it is more than a little bit longer - over 1/4" longer

None of these sizing steps require special case forming dies, and you can do this if you have a standard set of 8mm dies, and a good case trimmer. 

First step is to simply raise the 8mm sizer die about a quarter inch higher than the point where the lock ring contacts the press.  You also need to loosen the decapper pin and lower it about that much so that it reaches low enough to deprime the case.  Lube your cases, and run them through at this setting.  I didn't even lock the die down with the lock ring.

You are now left with your -06 cases neck sized down to the shoulder, and deprimed.  The next step is to trim off that substantial quarter inch of extra brass.  This would kind of a chore even with most of the lathe type trimmers, but I've got a little rig that makes it easy, and everybody oughta have one.  It's another one of those Lee products that is just too cheap and useful to not have.

It is the Lee Universal Three Jaw Chuck.  It will clamp on any cartridge head I've seen, and combined with a cordless drill, makes case trimming a breeze.  Matter of fact, case spinning for chamfering, deburring, and even polishing can be done all in one clamping and you're done.   

After the trimming, I hit the inside and outside of the case mouth with my chamfer/deburing tool, and was ready to finish squishing these things down to size. 

This could probably be done in one step, especially with the Rock Chucker and a sturdy bench, but I decided to take it easy on my self and split the job into two stages.  I screwed the die in about half the distance (1/8"), and also raised the decapping pin back where it belongs so that it didn't bottom on the case head. 

After running the brass through that stage, I simply threaded the die down to where the lock ring bottomed on the press and finished them all.  They came out looking great.  AND -- they chamber easily in my K-98.  Thanks for looking.  jd

I don't want to belong to any club that will accept me as a member.  Groucho Marx

Offline Adam7

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Re: Case Forming - 30-06 Gov to 8mm x 57 Mauser
« Reply #1 on: November 21, 2014, 10:38:43 PM »
Very cool.  Didn't look that difficult even though I don't reload.  Thanks for sharing!