Loaded rounds won't chamber 300 wm

Discussion in 'Reloading' started by Gatr, Dec 28, 2013.

  1. Gatr

    Gatr Well-Known Member

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    I have been reloading for my 300 win mag for about a year. I have been full length sizing and sizing with Lee dies. I wanted to neck size only after all the brass had been run through my new barrel ( second firing). I got a RCBS neck and seating die. I can use either sizing die with the Lee seating die and everything chambers fine. But with the RCBS seating die they will not chamber. I can't find any difference between the loaded rounds with calipers.Am i missing something or could I have a defective die?
    Thanks for your help
     
  2. Broz

    Broz Well-Known Member

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    Try backing the RCBS die out an additional 1/4 to 3/8 turn. It could be contacting the brass causing it to swell in the shoulder area.

    Jeff
     
  3. Freebore

    Freebore Well-Known Member

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    I suggest you check your brass wall thickness in the neck area. It should be uniform all the around. Ask the 'smith what is the neck diameter of the finished chamber. You may have to clean-up your brass in the neck by turning just hitting the high spots. This is not usual but not unusual either in a custom barrel with SAMMI Spec chamber. It could just be I'm sure a min spec chamber. So the brass has to be cleaned up of high spots.

    Yes it is possible you may have a bad seating die. Call RCBS pretty good folks there.

    I have that issue with a 220 Swift. Lee die wont bump shoulder back enough but RCBS will. A Min SAMMI Spec chamber.
     
  4. Gatr

    Gatr Well-Known Member

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    Broz,
    I backed it out about 5/8 of a turn and that seems to have fixed it. But now there is a gap between the ram and die. Is this okay? Thank you for your help. This has been driving me nuts.
     
  5. Broz

    Broz Well-Known Member

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    Yes it is ok. But you will need to use a consistent stroke to keep seating depth consistent. The reason I like a light cam over against the shell holder is to insure the same depth each time. But this only works with dies set up to do this like Redding comp dies and some others. You might get by with a set of redding stepped shell holders to drop the case .010" and still let you set up to touch the shell holder. But I am not sure about that.

    The other thing is to make sure your brass is trimmed to spec or close. If it has grown long you might trim it and be able to lower the die again. You will have to test and see.

    Best way to set that die up is to put a sized case in the shell holder and extend the ram to top. Then screw the die in until you feel it contact the case. Then back it out a little and lock it down. If the die bottoms out on the case it will push the neck in and swell the brass causing it to not chamber in the rifle. That was the problem.

    Glad you got her figured out. :)

    Jeff
     
  6. jimbires

    jimbires Well-Known Member

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    keep an eye on the ram as you lower the handle . some presses the ram actually goes down a little bit when the handle is completely down .
     
  7. Gatr

    Gatr Well-Known Member

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    Thanks for all the help guys! I've got it sorted out, thanks again broz
     
  8. LONGSHOOTER

    LONGSHOOTER Well-Known Member

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    It would benefit you to read the instructions that came with your RCBS die set.
     
  9. Gatr

    Gatr Well-Known Member

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    That's helpful. I read and reread them. The directions say not to let the die contact the shell holder. It was not contacting, but now there is about 3/16" gap. Much more than my other seating die.
    Thanks for your derogatory response, and lack of useful information.
     
  10. LONGSHOOTER

    LONGSHOOTER Well-Known Member

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    Not derogatory.

    And, the only lack of useful information, was in your lack of retention of information, from reading and rereading the instructions.

    If you really read and understood the instructions, then you would know what caused your problem.
     
  11. Gatr

    Gatr Well-Known Member

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    The directions never specified a 3/16" gap. I saw no evidence of crushing when I compared them to other loaded cases. I thought I had ruled out that issue by not letting the die contact the shell holder.

    I am still new to reloading and have been doing on my own by reading. I don't have it all figured out, which is why I came here looking for answers.

    If you need to talk down to people like me to feel better about yourself than by all means go ahead. There are plenty of people like "Broz" on here that more than make up for you.

    Again,
    Thanks for nothing.
     
  12. LONGSHOOTER

    LONGSHOOTER Well-Known Member

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    Alot of peeps run into problems because they don't understand their dies.

    The RCBS seater has an integral crimp feature that must be understood. Many don't give it any thought.

    Have you?
     
  13. Korhil78

    Korhil78 Well-Known Member

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    Wow..I hope that everyone on here treats you the same way when you ask a question.
     
  14. willy53

    willy53 New Member

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    How deep are you seating the rounds? Also how far is your bullet from the lans? Back the rcbs die out about a third of turn and try to chamber that round. If it chambers the rcbs die could be hitting the neck. So the rcbs die could be made a little different on the inside.