243AI question on fireforming

Discussion in 'Reloading' started by Sheep Hunter, Jan 27, 2008.

  1. Sheep Hunter

    Sheep Hunter Member

    Messages:
    18
    Joined:
    Dec 3, 2006
    I have a 243AI that is shooting lights out. The load is 45Grains of RL22 toped with a 105gr berger.

    It seems to be a little tight when the bolt is closed with the fireformed brass. My question is what steps do you take after fireforming the brass. And if there are no pressure signs should I change any thing. I am using this gun for hunting so I do not want any loading issues in the field.
     
  2. adam32

    adam32 Banned

    Messages:
    732
    Joined:
    Nov 14, 2007
    Are you full length or neck sizing them after they are fire formed?
     

  3. Sheep Hunter

    Sheep Hunter Member

    Messages:
    18
    Joined:
    Dec 3, 2006
    I am full length sizing, but only bumping it back 1thou. I am also trimming the neck to make sure they all start out the same length.

    Thanks
     
  4. J E Custom

    J E Custom Well-Known Member

    Messages:
    7,308
    Joined:
    Jul 29, 2004
    It is normal for the fire formed case to be a little tight because it has
    no headspace and totaly fills the chamber.

    If you want to avoid loading issues for hunting back off on your sizing
    die just a little untill you get the desired fit.

    If your neck sizing only it want help with the feeling of tightness.

    J E CUSTOM
     
  5. Sheep Hunter

    Sheep Hunter Member

    Messages:
    18
    Joined:
    Dec 3, 2006
    Thanks J E.
     
  6. 338hammer

    338hammer Well-Known Member

    Messages:
    51
    Joined:
    Jan 10, 2008
    243ai

    I am thinking that if one has a tight chamber then one has what could be called a benchrest quality chamber. When you say tight we really do not know what tight is unlee you say its leaving fine powder from the case on the bolt head. Maybe a bolt smear on the head of the case.
    In any cartridge if its tight, screw the die down tighter to the shell holder until the issue goes away. If the issue does not go away call your smith.

    Set back is normal when forming a factory case to an improved chamber. After the set back/headspace is correct then I use a neck die only. Careful about going to far in the set back as one can bulge the neck/shoulder juncture and make a tight fit as well. Typically when fire forming for the break opens I will have to set the shoulder .015-.020 back.

    338
     
  7. ddgo

    ddgo Well-Known Member

    Messages:
    49
    Joined:
    Jan 28, 2008
    Sheep hunter I have a 6mm AI tight neck that has had the same issue. I got a standard neck full length sizing die from Redding. The die will not size the necks on the tight neck, but it will bump the shoulder back to allow easy bolt closing. I use a set of redding shell holders that are different thickeness. Setting the die against the shellholder i find the one that allows for the feel that I want in closing the bolt.
    I then go back and size the neck with a Wilson bench rest die with the proper sizing bushing. This gives me the perfect fit I want.
    Hope this helps. ddgo
     
  8. shiredude

    shiredude Writers Guild

    Messages:
    170
    Joined:
    Aug 20, 2007
    You know I shoot 45 grains RE 22 behind 107 SMK's in my 243AI and it rocks em pretty good. One thing I have done is just neck size all my brass after a light fireforming load. THis has shut down the tight chamber issues that I was having.
     
  9. Sheep Hunter

    Sheep Hunter Member

    Messages:
    18
    Joined:
    Dec 3, 2006
    Thanks for everyones help.