adjusting die for a belted magnum?

Discussion in 'Reloading' started by desertbull, Feb 6, 2011.

  1. desertbull

    desertbull Well-Known Member

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    OK, I'm just getting my reloading bench set up. I have the all the basics to get started...rockchucker, Forster FL die and Forster seater. I will only be reloading for 7MM Mag to start.

    The instructions on the forster FL die says to screw the die down until it touches the shell holder then lock it down. Is this the recommended method? I think I want to head space off the shoulder, not the belt, correct?
     
  2. desertbull

    desertbull Well-Known Member

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    Sorry, I did not see the existing thread on this subject. After reading through it, there was not much info, just a lot of arguing.
     
    Last edited: Feb 6, 2011

  3. jimbires

    jimbires Well-Known Member

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    you want to adjust the die so you push the shoulder back about .002 . resize the belted case just the same as a non belted case . make it head space off the shoulder and you'll be fine . Jim
     
  4. desertbull

    desertbull Well-Known Member

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    So I should not do as Forster suggests and turn the die down unit it makes full contact with the shell holder?
     
  5. jimbires

    jimbires Well-Known Member

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    do you have a way to measure the case length , from the case head to the shoulder ? this would be like a RCBS precision mic . if you do then you want to adj the die down a little at a time until you "bump" the shoulder back about .002 " . I use the redding competition shell holder set with a precision mic to accomplish this . this is the best and safest method . if you don't have a way to measure the shoulder bump then I guess all you can do is adj the die as per the directions . keep in mind you could be setting the shoulder back way more than needed and this will shorten brass case life . Jim
     
  6. Johnboy

    Johnboy Well-Known Member

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    this is what you can do.if its for a remington 700 pull the fireing pin out of the bolt.now run the FL die in till it just touches the shell holder.with a fired case lube it up all the way to the shoulder and inside of the neck.now run the case into the die,then wipe off the lube with a rag and run the sized case into the chamber with the bolt. ( without the fireing pine ) you are looking for the bolt handle to close without help at all.some will say for it to be alittle tight but not so much you have to really be the reason for the bolt handle to close.if the bolt does not close as said now screw the die down alittle more and repet the test fit.one thing to help with how much you turn the die in is too put an index mark on the die.this will help you to see just how much you turn the die in each time.for the most part of this it should be about a 1/4 to 3/8 more of a turn from the first setting of the die at just touching the shell holder.just keep turning in the die alittle at a time while relubeing and checking each time till you get to the point of little or no reresistance on the bolt.

    now after all said and done and the bolt closes with little to no resistance you have pushed the shoulder back just enough to have the right amout of headspace to keep things just right.and now the belted case is useing a false headspace rather than useing the real headspace area.( the belt )this way seems to work great for me and I have no gauge at all.but I am not loading for longrange matches either.just like to keep my groups as tight as I can without haveing to by more stuff to keep up with.and if you are able to neck size your brass I would only do this one step till about the 5TH fireing or till the bolt seems to be alittle harder to close on a loaded round.but do not get confused between a jamed fitted bullt and a case that needs to be bumped back in the shoulder area for a better fittting case.

    one more thing to remember.one does not want to over bump the shoulder area to many times.this will cause the case head to separate.and thats not a good thing.just hope that I was able to help you out.

    John
     
  7. desertbull

    desertbull Well-Known Member

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    No, not at this time. I have the tools from Hornady to measure headspace and COAL.
     
  8. desertbull

    desertbull Well-Known Member

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    Thanks. My rifle is at MCR right now getting a new barrel and other work. I was just trying to get some brass prepped for when I get it back.

    I have a bunch of once fired brass from the original barrel I was hoping to use.
     
  9. boomtube

    boomtube Well-Known Member

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    "I have the tools from Hornady to measure headspace and COAL." Those will do the same job as the RCBS Precison Mic, use them instead.

    Forget how the factories cut a chamber for the correct headspace. Rims and belts are irrelivant to reloaders, just use your Hornady tools and your precision caliper to set your sizer die as it should be, it's all done the same way for ANY bottle neck case.

    Measure a few fired cases to find the head-to-shoulder length. Absolute precision isn't required but you do need to establish the relitive number with consistancy. Once you find the longest fired case, simply size so the finished shoulders are no longer than that longest length and you're done.

    You will find some variation in individual cases, both fired and sized. That's due to differences in the springback of individual cases. DON'T 'average' them, that only obscures things, just make sure your longest resized cases are no longer than the fired ones.
     
  10. MSLRHunter

    MSLRHunter Well-Known Member

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    Just for your information, when I get my dies set up right to just barely bump that shoulder back, there is about 1/8" to 1/16" of space between the bottom of the die and the shellholder.

    +1 with what Boomtube said.