Small Base vs Standard Die

Discussion in 'Reloading Forum (All Calibers)' started by C.E.Smith043, Oct 7, 2018.

  1. C.E.Smith043

    C.E.Smith043 Gold $$ Contributor

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    Ive been fooling around with a Redding FL Die and a RCBS Small Base Die set for my AR-15 in .223. I set both of these up to bump my shoulder .003"

    But here is where im confused. I cannot find where at on the case the Small Base Die resizes the case any smaller than my Redding FL Die.

    What portion of the case is the Small Base Die supposed to resize differntly or smaller than my standard Redding FL Die?

    From my measuremnets all of the dimensions are coming out the same.
     
  2. Doug Beach

    Doug Beach Silver $$ Contributor

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    If there is a difference, it will be in body diameter, specifically in the sized portion closest to the case head.
    I don’t believe there is an industry standard for a “small base” die, so overlap of standard and small base between brands is not surprising.
     
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  3. C.E.Smith043

    C.E.Smith043 Gold $$ Contributor

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    this very well may be the case in my situation. Thank you so much for your reply
     
  4. fguffey

    fguffey

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    Most reloaders forget about the shell holder, the shell holder has a deck height, again, it is a burden but I must be the only reloader that measured the deck height of the shell holder. I use shell holders with a deck height of .125". A shell holder with a deck height of .125" can be used with any die manufactured sense 1960 +/- a year or two.

    So? I do not know what part of the case head you are measuring but it is impossible to size any part of the case head below .125" because of the deck height of the shell holder. After that there is another consideration, the die had a radius, the radius prevents the die from sizing the case head below .125 + the radius. And then there is a great big problem with reloaders, rather than think about it they had rather act silly.

    There is no shortage of small base dies around here, it is not fair but I find it most difficult to measure the difference between cases sized with a small base ide and a 'good fitting' standard die.

    Before the Internet and anti social media: There were different chambers meaning the same ammo that was designed to be fired in the 03 and M1917 was issued to be used in the M1 Garand. I could ask, "How could that be?' but I am not in a crowd that would understand the question.

    And then there was Browning, Browning made semi/auto 30/06, 270s, 300 win Mags etc.. and I ask , "What was a reloader to do?", Anyhow I have 6 sets of dies that are labeled BAR dies. The BAR identified the dies as small base dies for Browning Automatic Rifles.

    I could ask: What to do if a reloaders does not have small base dies? I have used the feeler gage between the deck of the shell holder and case head to increase the ability of the press to overcome the ability of the case to resist sizing and increase the ability of the press/die to shorten the case from the shoulder to the case head. This method has never failed me. Other reloaders? They spend all of their time 'bumping' and talking about it. I cant talk about bumping the shoulder because I can not bump the shoulder with a die that has case body support.

    F. Guffey
     
  5. fguffey

    fguffey

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    Even more surprising would be to find a reloader that can measure the difference. I am going through a pile of micrometers, close to 80 in all that I intend to sell them. It is not easy to get them 'all' to agree.

    F. Guffey
     
    Last edited: Oct 7, 2018
  6. GSPV

    GSPV A failure to plan is a plan for failure. Gold $$ Contributor

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  7. Keith Glasscock

    Keith Glasscock True believer - Straight 284 Gold $$ Contributor

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    I just bought a small base die in 284 Win from Redding. The matching FL die leaves the case head, fwd of the groove at .5007" the small-base body die leaves them at .5000"

    The difference isn't much, but I'm using it to see if I can get rid of the click at the top of bolt lift on my "tighter" chamber jobs after firing the brass in a "looser" chamber.
     
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  8. Bc'z

    Bc'z Gold $$ Contributor

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    Ok Guff explain me this scenario.
    So once upon a time, we shot some new military surplus ammo thru wifes ar.
    After thorough case prep including trim to 1.75, I commenced to load some rounds to test in BOTH our ar's using hornady's custom series 223FL dies.
    Long story short rounds would not go into battery in my POF but cycled just fine in my wifes.
    Both rifles shoot 556/223.
    Anyhow I purchased a set of
    rcbs small base dies, problem solved.
    Same shell holder, no I've never measured it.
     
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  9. dkhunt14

    dkhunt14

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    You are correct. It isnt much but sometimes .0005 is all you need. Matt
     
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  10. jepp2

    jepp2 Gold $$ Contributor

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    Were you having a problem the Redding FL die wasn't properly sizing the case? I have a small base RCBS die set that I have never seen the need to remove the rust preservative from. I bought them fairly early on when I started loading for various AR's and have just never seen a need for them.

    Yes, I recognize there are folks that will swear you MUST use small base dies on all brass going into AR's.
     
  11. Mark204

    Mark204

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    Here's what I find the most baffling and bizarre........Who has 80 micrometers and 200 shell holders? I would think at that point the "reloader" should probably find a different hobby, maybe bowling or horseshoes??


    Mark
     
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  12. C.E.Smith043

    C.E.Smith043 Gold $$ Contributor

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    No problems...i have just had that set of small base dies for 10 years now and they have never been out of the box. So, i decided to just get them out and actually see if i could see any difference than the Redding FL dies ive been using for 18 years.
     
  13. luckeeshot

    luckeeshot Gold $$ Contributor

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    maybe it's time for a intervention for F.G. he must be a hoarder :confused:
     
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  14. 243winxb

    243winxb

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    Set both dies to cam over on the shell holder, then measure head to datum and other areas. May prove interesting?

    Just for a test. I dont know the answer.
     
  15. Medic505

    Medic505 Dean Wheeler Gold $$ Contributor

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    I'm confused, do we as reloaders increase or overcome?
     
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  16. Uncle Ed

    Uncle Ed

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    Below is a Forster explanation for the three .308 dies, and for the several .223 dies I have the small base die is .002 to .003 smaller in diameter for the total body diameter. Meaning it reduces the case to minimum SAAMI dimensions.

    "BUT" dies vary is size, example I have a standard Lee .223 full length die that will reduce the case diameter "more" than my RCBS .223 small base die.

    A case resized for a semi-auto should be .003 to .005 smaller than its fired diameter. This allows the case to spring back from the chamber walls and extract reliably.





    [​IMG]

    Below I use the red JP Enterprise gauge for a plop test for my AR15 rifles reloads. Below the red JP Enterprise gauge is made to minimum dimensions and is a smaller diameter. Meaning no matter what type die if the case fits in the JP Enterprise case gauge it will function in any AR15 rifle.

    [​IMG]
     
    Last edited: Oct 7, 2018
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  17. SPJ

    SPJ Silver $$ Contributor

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    Wouldn't it be nice if every rifle came with the reamer print
     
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  18. C.E.Smith043

    C.E.Smith043 Gold $$ Contributor

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    Thank you so much. This is very helpful.
     
  19. JSH

    JSH

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    I went to SB dies for reliability. One in a thousand cause me issues is to many. I am not a big AR shooter, but I want it to go bang, or get ejected EASILY if it doesn't.

    Y'all want strange/odd or goofy. My brass out of my tight chamber bolt gun will not chamber in my BM AR unless run through a SB die. YMMV
    Jeff
     
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  20. alinwa

    alinwa

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    Makes no difference...... 50 chambers cut between centers on the same mo'chine at the factory would be different diameters
     

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