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50BMG Primer seating problem

Discussion in 'Handloading and Reloading' started by total recoil, Jun 15, 2013.

  1. total recoil

    total recoil Member

    Jul 30, 2010
    I have a Lee Classic press for 50BMG loading. I have a K&M primer pocket uniformer that machines the primer pocket to look like new brass. I even champfer the top edge of the hole to make starting easier. I use lacquer on the primer pocker to seal and act as a lubricant in seating the primers. Sometimes this happens and it happens too often. The primer seats hard. There is no way of looking at it unless you continue seating it till it's too late. When you can finally get the brass out of the shell holder it looks like this.
    These are the only primers on the market and very expensive. Lee, unfortunately has no instructions for setting up their 50BMG priming station and I have a feeling that there is a reason. What am I doing wrong that causes such destruction? Help!
    How does on put a picture into the body of his letter???

    Attached Files:

  2. rcmodel

    rcmodel Member in memoriam

    Sep 17, 2007
    Eastern KS
    I have never reloaded .50 cal.


    I can see no evidence in the photo that all the military crimp was removed from the primer pocket before seating.

    You said you did, but it isn't evident in the photo.

    And a remnant of the crimp, or all of the crimp left over will cause exactly the problem you are having in any military caliber brass.

    You 110% sure you reamed the crimp in those cases??

  3. GLOOB

    GLOOB Mentor

    Sep 16, 2007
    If you feel something off, can you carefully push the primer back out with a decapping pin? Then you could ream/chamfer the pocket some more. Whenever I prime my 223, I keep a chamfer tool by the press, just in case.

    Also, maybe it's just me, but I don't think lacquer is a very good lubricant? Maybe you could try adding the lacquer after the primer is seated.
  4. Jesse Heywood

    Jesse Heywood Senior Member

    Dec 9, 2009
    Do you have pics of the pocket before installing the primer?
  5. 50 Shooter

    50 Shooter member

    Dec 24, 2002
    SoCal PRK
    Did you measure the primer pocket uniformer before using it? I'm with RC, if you ream you need to get rid of the the ring crimp on those. Older brass has staked primers and are easier to tell when enough material has been removed.

    Stay away from lacquer, seat the primer on its own so that nothing else is interfering with it. Don't use the brass in the picture, those primers have issues and you don't need any more problems. There's also a flat and domed primer seater, make sure you use the right one. The CCI 35's do better with the flat seater, that way you can feel them hit bottom and flatten them a little to arm them.

    Post a pic of your brass pre primed, you only need to remove a little material but it has to be enough for the primer to go in. Then run your uniformer in until it bottoms out on the back of the case.
  6. FROGO207

    FROGO207 Mentor

    Dec 7, 2008
    Mount Desert Island Maine
    I do not load for the big fifty but on the standard MIL SPEC stuff a slight bevel on the finished round works wonders. The RCBS and C4HD swadgers I use both round the entrance of the pocket some. I see at best a removed crimp and no bevel. Try a couple with a bevel using your chamfer deburr tool that works on smaller brass if you have one.
  7. CharlieDeltaJuliet

    CharlieDeltaJuliet Participating Member

    Apr 10, 2012
    North Carolinian
    The primer pocket needs more reaming. I had that problem a few years ago when I started reloading the 50 BMG. It is just simply flattening the primers rather than seating them. You will think you have "over reamed" the pocket when you get the military crimp out...

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