is it normal ???

Discussion in 'Reloading' started by Freedom2live, Mar 7, 2013.

  1. Freedom2live

    Freedom2live Banned

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    Hi new to reloading , stupid question is I measure my 243 empty case and they all read 2.044 after shooting them. Later on I full length size them and they read 2.048. Stupid question is this normal
    the book says 2.045 length is the standard ??. So I have to trim them down to standard right.. ? Am lost
     
  2. J E Custom

    J E Custom Well-Known Member

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    You don,t have to trim as long as the neck chamber is longer.

    I like to do a cerrosafe casting of the chamber unless I have the reamer that was used to chamber
    it with.

    Cerrosafe can be bought from Brownell's and re used many times. It can be melted with a hot air gun
    or hot water.

    After you cast the chamber you can measure the maximum neck length you can use. (It is
    recommended that the case necks be .020 shorter than the neck chamber.

    Another test is to take a the bullet that you use in your load and try to insert it in a fired case,
    if it doesn't want to go the case necks are probably to long and must be trimmed .020 to .030 .

    J E CUSTOM
     

  3. Lefty7mmstw

    Lefty7mmstw Well-Known Member

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    another nice thing about a chamber casting is that you will know your true dimensions and if there is any taper in the throat area or end of the chamber you need to be aware of...
    I haven't worked with cerro-safe myself(rem did cast a chamber for me that was trouble once though), but I should probably get some to be able to find those little issues you run into from time to time.

    As to growth when you re-size, yes it is normal. I have one rifle that grows .020" the first firing, then it settles down(with the dies properly set) to .003" per firing. Most rifles will be less than my example.
     
  4. Freedom2live

    Freedom2live Banned

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    Thanks guys very. Much .. It is normal for it to greater fulllenght sizing.. I thought I was seeing things
     
  5. westcliffe01

    westcliffe01 Well-Known Member

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    Have you considered what you are doing when you full length size?

    You force the body of the die over the outside of the cartridge and the "slug" of the neck sizer through the neck (it goes in easy since the neck is expanded after firing). The body of the die compresses the diameter of the cartridge a little smaller, since it expanded to fill the chamber, particularly near the front. The top part of the die (the neck area) shrinks the neck of the cartridge smaller than the final diameter it needs to be.

    Then when you raise the die, the slug passes through the inside of the neck from the bottom to the top, expanding it to the correct inside diameter to fit the bullet. The fact that you pull it through from the bottom to the top, is why the neck becomes longer (one of the reasons). The second reason is that if you fire high pressure loads, the brass will actually flow as if it was putty from the bottom to the top because of the effect of the high pressure/ velocity gases.

    You would do well to trim all your brass exactly the same length. Then if you check the length after it is fired, you get a good feeling for the impact your loads have on it. The more lengthening you see, the shorter the life of the brass will be before you have to throw it away. If your head space is "loose" the bottom of the cartridge will also expand until it touches the bolt face and when you re-size it the part that stretched does not become thicker again. Next time you shoot it, it stretches again and gets thinner still. Only so much of this can go on before is ruptures and that will not be a good day for you....

    So if you are shooting a bolt gun or a single shot, do NOT full length re-size. Just get a Lee collet type neck sizer and use it to shrink the neck only. Your brass should fit your chamber perfectly and if you do this it will last much longer.
     
  6. Lefty7mmstw

    Lefty7mmstw Well-Known Member

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    I FL size everything; I want it to actually chamber when I'm hunting. That said, I adjust my dies to the rifle. I can usually get it down to a couple of thou. growth.

    I must digress about the expander ball comment; if your necks are properly lubed the expander ball does nearly nothing to grow a neck. Run that sucker through on a highly carboned up dry neck and it's another story though; it's all a matter of using your tools correctly. The main growth factors are the brass's diameter change between fired and sized and the length of the brass being corrected shorter for headspace. That is usually less than .003" total growth.
     
  7. Freedom2live

    Freedom2live Banned

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    Really .. I noticed on some other brass manufactured they grow up to 2.055 from 2.044.. That's a lot . I ordered a neck sizing die yesterday ..
     
  8. woodnut

    woodnut Well-Known Member

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    First, welcome to world of reloading! Second, the only stupid question is one not asked. You asked a very good question.
    Someone said if you couldn't put a bullet into a fired case, it probably was too long. Not sure what he intended to say, but that statement isn't quite correct. If it won't drop in/through, the neck wall is too THICK. You'll need to turn the case necks then, not trim to length. Length and the neck thickness are set by your chamber (and throat and/or freebore). You need to check that neck diameter by dropping a bullet through a fired case. If it goes , good, if not , it needs turning. Unless your rifle is a custom build, the chances of that step being needed is slim. However, since it is a .243, you probably will run into a need for trimming later. The case has a lot of taper and the brass will flow at firing. Re-read some of these posts for good info. Then read the reloading manuals about reloading and they will give you some very good advise. Not just one book, but several to get other professional advise and opinions.
    You have also discovered that brass quality varies from different mfg. Once you get more familiar with / into reloading , there's lots of things you can add to your basic steps to improve reliability and accuracy.
    Don't stop asking questions!
     
  9. J E Custom

    J E Custom Well-Known Member

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    Thanks ;I should have explained better.

    This has nothing to do with expander ball diameter or case neck thickness, it is a condition of
    to long cases for the chamber.

    When a neck is to long it will not expand at the case mouth when fired. It looks and acts like it
    was crimped. The rest of the neck can be the correct diameter but the mouth of the neck will
    be to small to except the bullet.

    After you trim .020 to .030 the bullet should drop right in.

    This condition will also cause excessive pressure.

    J E CUSTOM
     
  10. Freedom2live

    Freedom2live Banned

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    Also has anyone reloaded .243 105gr hunting vld .?? I noticed the bullet is touching the lands at 2.978 the book says oal standard size 2.710.. Can I be somewhat safe shooting these round that close to lands ???? .. am starting with start loads imr 4350 over federal match gold 210 primer..
     
  11. jasent

    jasent Well-Known Member

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    Seating depth depends on your rifle. The ones listed in your Manuel are for bullets that can fit any gun. Find out where your rifling is and seat them .005 shorter than that. That is normally a good starting point but if that won't fit your magazine (such is the case in my 243 with Berger 105 vld's) then start at a seating depth that functions in your mag. Then work up your load and after you decide on a charge you can play with seating depth to possibly tighten you groups
     
  12. Freedom2live

    Freedom2live Banned

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    Jesus what great information I just received . I am truly blessed to hear so many valid points..
     
  13. jasent

    jasent Well-Known Member

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  14. Freedom2live

    Freedom2live Banned

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    Jasent. I can't thank you enough for that link... Outstanding