Forster Bump Die help

Discussion in 'Reloading Forum (All Calibers)' started by Ram, Jan 19, 2010.

  1. Ram

    Ram

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    I purchased a Forster bushing bump sizing die in .308 and I think there is a problem with the die or I don't understand how it works.

    The case sizing instructions state that the die should be positioned to ensure that the die makes complete contact with the shell holder. However, with a fully resized case (two different FL dies) and without the neck bushing, the case shoulder makes contact with the die while the case protrudes outside of the die by 0.135". With a standard shell holder dimension of 0.125", this will push the shoulder back up to 0.010" below minimum.

    What am I missing here? If its a matter of moving the die away from the shell holder to bump the shoulder as needed, I'm a bit upset in that I can't use my Redding competition shell holders to control the shoulder bump.
     
  2. Ram

    Ram

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    Does anyone have a Forster bump die, and how do you adjust the die position to bump the shoulder consistently (repeatable) without the shell holder contacting the die?
     
  3. jo191145

    jo191145 Site $$ Contributor

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    Ram

    Never had a Forster bumper. I made my own by stoning down my shellholders and using standard Redding necksizers. Works just fine.

    First. You state you have Redding Comp shellholders. They supposedly increase in thickness in .005" increments. They should work for you. Never had a need for them myself.

    All my homemade bump dies do not contact the shellholder. Neither do my FL dies. Personally I would'nt want them to.
    Mine are all set to the correct headspace using the locking stop collar on the die. Takes a little fine tuning to get them in the .001" area but its not that hard. Once its headspaced correctly lock the ring. Repeatability is not an issue unless you have two guns with different headspace measurments.

    You need to set your headspace to bump the shoulders back .001''- .0015" on fired brass not FL sized brass. I'm assuming these FL dies were set up according to instructions (contact shell holder plus 1/4 turn) Or something similar. Throw all those instructions in the trash!!!

    Any die that touches the shoulders should be set to bump .001"-.0015" under chamber dimensions. Wether or not your hitting the shellholder at that dimension is irrelevant.
     
  4. Ram

    Ram

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    The only Redding competition shell holder that could work is the +0.010 which would get me to the minimum length. Since my chamber is more than 0.002" above minimum, even the +0.010 will over work my brass. I like the shell holder to touch the brass since i know this is repeatable.
     
  5. Mikem

    Mikem

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    Take a fire formed case or two, and take a case headspace reading on them, they should be the same, then deduct .002.
    Now remove the neck bushing and adjust the die in your press, with the shell holder you will be using, to bump the shoulder back to your FF reading less .002, and lock it. Then set the neck bushing to size as much of the case neck as you want.
    Now every time you neck size a case, you will bump the shoulder back .002. I set my 6BR at .0015.
    You do have a stony Point (Hornady) case comparator tool?
    This die will not size the case body, for this, I recommend using a Redding body only die, when needed.
    Mike.
     
  6. Gearheadpyro

    Gearheadpyro

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    +1 to Mikem, you beat me by 30 seconds.

    My Forster bump die does not touch the shellholder when it bumps the brass. I bump the brass .002"
     
  7. jo191145

    jo191145 Site $$ Contributor

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    Sorry Ram, I was'nt aware the Redding comps only went up to .010".

    I can't think of an easy fix to headspace your brass correctly and use the shellholder as a stop at the same time. Headspace always rules.
    Locking the die above shellholder contact works for me just fine. Most of my sizing dies do not touch the shell holders when used. Its even possible none of them do.
     
  8. Mikem

    Mikem

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    Gearhead, I know what your talking about, Ive had it happen several times. Being a few sec late I mean.

    This Forester die is hard to find right now, some sites dont even show it, and im not sure why, I dont think its that new. Its also different than most dies, so setting them up the first time is different, and can be a bit confusing. As well as some instructions are hard to follow, so this question doesn't surprise me at all.
    I only have one of these dies, and its marked 6BR, but by changing the neck bushing, I also use it on 22BR cases, and it might also work on 30BR, but haven't tried that, I dont have a 30BR.
    Mike.
     
  9. Joe O

    Joe O

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    I had a litttle trouble setting up my first ever Bump shoulder,beck bushing die,by Forster.I have a Sinclair shoulder gage for my .204ruger,and 243AI.I use the measurement from a once fired case,and set my die to that measurement.A wilson case gauge would work as well.
     
  10. Ram

    Ram

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    Why would Forster make a die that places the shoulder at a different position, relative to the bottom of the die, than the industry standard? I'll adjust the die using the suggestions here. Thanks!
     
  11. Mikem

    Mikem

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    Ram, its your die and brass, so you can set it anyway you wont. But the more you move the brass around, the shorter its life will be, but hay, its your brass.
    You must think all chambers are the same. But apparently Forester doesn't think that, and that not everyone wants the same case to chamber fit.

    And remember this die doesn't resize the body of the case at all, so if you want "industry standards", you should be using a standard FL sizing die.
    Mike.
     
  12. NorCalMikie

    NorCalMikie Site $$ Contributor

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    I just checked my Forster Bushing Bump die and it in fact does contact the shell holder with a "very slight" cam over. That's where I've set the headspace on "my" Savage Rifles.
    It's consistant and every time I switch dies, they always go back to the same place. Slight cam over. You might not be able to do that on a different type of rifle (Remington, etc.) but it works on all of my Savage barrels. Bump the shoulder from there, maybe .0015 to .002, size the neck, load them up and go shooting. ;)
     
  13. RonAKA

    RonAKA

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    I have the Forster bump die and had not reloaded in a couple of years. I had exactly the same question, and found your thread when looking for some help. Unfortunately the Forster instructions leave out any information on how to change the bump. As you say, all they note is to have the shell holder fully contact the die body.

    I'm loading 6BR, and I took a few measurements of a fired case in the die up against the bump shoulder. I sized a case following their instructions to hard contact the die and measured it again. It was 0.001" shorter. So in my case for whatever reason the bump is right on what I want it to be.

    I also measured the overall length with the shell holder removed and hard against the die with no cartridge in place. I then measured the same way but with a fired but not sized case in the die. It showed that the shell holder was 0.006" clear of the die.

    What I can conclude from this is that at least in the case of the 6BR case you have to scrunch the case by 0.006" to get 0.001" bump after spring back.

    So part of the discrepancy that you are seeing is the allowance for spring back. However, if the die is bumping the shoulder too much you either have to use a thicker than standard shell holder, or you short stroke the press so it comes the appropriate amount short of holder to die contact.

    If you want to bump more then the only option would be to remove material from the shell holder face or buy thinner than standard shell holders.

    It is too bad that Forster do not explain this more clearly in their instructions. Also it seems a strange coincidence that I am getting exactly the bump I desire. This would seem to indicated that my headspace is only 0.001" larger than the very minimum. It makes my reloading die setting very easy and repeatable.
     

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