problem resizing for head space.

Discussion in 'Reloading' started by RangerBrad, Oct 12, 2012.

  1. RangerBrad

    RangerBrad Well-Known Member

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    I'm trying to resize my 1x brass for head space using a redding full length die but the oppisite keeps happening. The shoulder keeps growing longer. Some of yal may have read another recent post I made where I stuck a case in this same die. Could it be that I'm not lubing it enough and as it's being withdrawn from the die it's pulling it longer somehow? I'm stumped. Any ideas? Thank's, Brad
     
  2. Bullet bumper

    Bullet bumper Well-Known Member

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    If it's an old fashioned full length die with an expander ball then yes that can happen. If you are not cleaning and lubricating the inside of the neck well then the friction of the expander ball coming out can draw the shoulder out a few thou.
    Clean up inside the necks with an old worn bore brush wrapped with a small amount of steel wool. Chuck it in a battery operated screw driver .
    Then buy some moly powder and fine graphite and mix together at 50 50 ratio.
    With the case clean inside the neck and outside of the case run your fingers around the case neck to put some body grease on the case neck then dunk the necks into the powder . Tap the case to removes excess but not so hard that you nock it all off .
    Then roll on your sizing lube onto the body off the case.
    Size the case a bit at a time adjusting teh die down in small amounts until it will chamber with just some resistance on the bolt then turn the die down 1/32 of a turn more and size again. The bolt should then close easy and you have minimum headspace or fairly tight headspace . On a 7/8 x 14 threaded die , 1/32 of a turn = about .002 movement .
    1/16 of a turn = about .0045 movement.
    For comparison only the full headspace tolerance for a 308W is about .008 , 1/8 of a turn is .0089 so you see how easy it is to size too much by screwing the die down too greater amount when the case is close to the correct fit .
    In a bolt action you want the case to fit back in the the minmum amount of headspace but in a lever or auto it may be better to add a few extra thou to aid reliable operation.
     

  3. AZShooter

    AZShooter Well-Known Member

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    As a control remove the sizer ball and size. If you are partial full length sizing by setting the die so it doesn't touch the shell holder you just haven't moved it close enough to the shell holder. As the FL die is adjusted downwards at some point it will actually make the brass a worse fit than the fired case.(the die is dealing with the body taper and hasn't moved the shoulder back) All that is required is to continue to move the die down in partial turns till the die also bumps the shoulder. Do this till the sized brass fits the chamber to your satisfaction.

    There is a possibility if you are now touching the shell holder that the brass is still not sized enough. I have had a few barrels chambered by my gunsmith that were right on the edge of having too short a chamber. Camming over the top can sometimes do the trick. I had one rifle that required some grinding of the top of the shell holder till the brass could be sized sufficiently. Shell holders are cheap, or you can buy a set of different thickness shell holders from Sinclair.

    I could be wrong on the cause of your problem.Give this a try. Let us know what you find.
     
  4. ICANHITHIMMAN

    ICANHITHIMMAN Well-Known Member

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    Brad

    When you got the die, did you pull it apart and degrease it? Make sure if you didn't you do it now. When you have it apart polish all the parts.
     
  5. RangerBrad

    RangerBrad Well-Known Member

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    This is an Sbushing die with the expander ball removed. I did not clean the inside of the die. I checked the die at some point in the sizing process while I was lowering it to set the shoulder back enough and found htat I had already set the die further in the press than it's supposed to be and the shoulders appear to be getting longer. It is extremly hard to run the brass through the die. Any ideas? Brad
     
  6. Joe King

    Joe King Well-Known Member

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    Brad, from what you've written I believe that you have a very tight chamber and short of grinding down the bottom of your die or top of the shell holder, you really need to look at getting one of these sets appropriate to your case head dia. If I'm right this will allow you to set your die to size the cases to fit your chamber.

    Redding Competition Shellholder Set #6 (7mm Remington Mag 300
     
  7. Broz

    Broz Well-Known Member

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    Plus 1, I use redding competition bushing dies and have a set of these stepped shell holders for all caliber I load. Then just set the die to actually contact the shell holder with a little cam over at the end of the stroke. Use the stepped shell holders to adjust the amount of set back desired. Once you have the desired set back, die set up is fast and easy each time as you set it up at zero clearence. Simply use the same shell holder each time.

    Jeff
     
  8. boomtube

    boomtube Well-Known Member

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    "Dirty" sizer dies don't push shoulders forward more than normal.
    Normal expander neck drag doesn't pull shoulders forward.
    Redding's Comp. shell holders limits, not increases, how far a case can enter the sizer.

    The failure to set case shoulders back far enough usually happens when the user is 'adjusting' his die according to 'instructions' rather than what's needed. It's very likely turning the sizer down another 1/16th (4.5 thou) or 18th (9 thou) turn will fix the problem.
     
  9. Joe King

    Joe King Well-Known Member

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    That's assuming that the die isn't already contacting the shell holder, I'm betting it is, so he some how needs to get the case a bit further into the sizing die.
     
  10. Bart B

    Bart B Well-Known Member

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    Brad, if you can't set fired case shoulders back far enough with the die and shell holders you have, your rifle chamber may well be a bit short. Others have mentioned this.

    I'll add that if it's a standard cartridge headspacing on its shoulder, I'd find a friendly gunsmith to stick a GO headspace gauge in it and see if the chamber's too short. Then you'll have all the good information and be able to do one of two things:

    * Get a shorter/lower shell holder; .120" perhaps, instead of the standard .125".

    * Grind off a few thousandths off the bottom of your sizing die or the top of your shellholder.

    There's a slight chance the die's chambered a bit too deep and it's relative headspace to the shell holder is too long. One can also use a headspace gauge to check this out Most full length sizing dies won't let a GO headspace gauge fit in them with their bottom against the shell holder. This is what's needed to set the fired case shoulder back some nominal amount.

    I once put a .270 Win. barrel from an old Model 70 into a newer one and it had .003" too short of headspace. My full length sizing die barely set fired case shoulders back enough to let the bolt close. I took about .005" off the bottom of the die and it worked out well. Most factory ammo would chamber in that barrel with no bolt binding at all.
     
  11. Mikecr

    Mikecr Well-Known Member

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    RangerBrad, you have two signs of oversizing:
    -wedging/stuck cases
    -failure to headspace
    Other signs will be donuts & frequent need for trimming.

    How much is the brass changing in dimension from first firing?
    You might finish the fireforming & send 3 unsized cases to JLC Precision for a custom die.

    I had the same signs with Tubb's 'Ferrari of die sets' in 6XC, fired from a Tubb2000.
    I was using sizing wax which left cases stuck. Fixed with RCBS Case Lube.
    Headspacing was all over the map. Fixed with a JLC bushing bump die.
    Jim said my fireformed brass indicated a chamber completely incompatibile with Tubb's dies(gross oversizing).
    To be fair, McMillan Bros cut the chamber, not Tubb.
     
  12. boomtube

    boomtube Well-Known Member

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    "The failure to set case shoulders back far enough usually happens when the user is 'adjusting' his die according to 'instructions' "

    "That's assuming that the die isn't already contacting the shell holder, I'm betting it is, .."

    And I'd bet it isn't, not while under the full ram pressure of FL sizing which is what I'm recognising.
     
  13. Broz

    Broz Well-Known Member

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    Your correct about the shell holders limiting. The die needs to contact the Redding shell holder with a camover at the end of the press stroke. This is per reddings advice over the phone. And back then, at the time the dies had just came out, instructions that came with the bushing dies did not disclose this. Doing the the way I described will make dies set up easy, fast and consistant. Plus I will bet it will cure the problem with not enough shoulder set back.

    Jeff