Help , split case necks

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by Aussie, Nov 1, 2004.

  1. Aussie

    Aussie Well-Known Member

    Messages:
    250
    Joined:
    Apr 29, 2004
    I have a friend with a CZ 550 in .22/250 . Using Winchester brass and splitting most case necks on the second firing . Can anyone advise what sort of neck expansion should be expected on a .22/250 factory rifle when comparing fired vs loaded rounds ?
    Not sure whether we have an oversize chamber or a batch of hard brass . [​IMG]
     
  2. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

    Messages:
    6,848
    Joined:
    Jun 12, 2004
    Aussie,

    Most factory chambers will allow a case neck to open up anywhere from around 0.006" total expansion(0.003" all directions) up to as loose as 0.015" which is as bad as I have seen in my shop. Most are in the 0.008" to 0.010" range.

    If he is using virgin brass ans having case necks splits on the second firing, there is something wrong in the set up.

    Good Shooting!!

    Kirby Allen(50)
     
  3. LB

    LB Well-Known Member

    Messages:
    423
    Joined:
    Jul 22, 2004
    I think a too slow powder and very light for caliber bullets can cause something that looks like a split neck. LB
     
  4. Aussie

    Aussie Well-Known Member

    Messages:
    250
    Joined:
    Apr 29, 2004
    Kirby ,
    Thanks , I'll do some measuring .
    LB , Using 760 and 50-52 gn pills . Nothing unusual about the load
     
  5. Aussie

    Aussie Well-Known Member

    Messages:
    250
    Joined:
    Apr 29, 2004
    Kirby ,
    Necks on loaded rounds average .250 , fired cases are .257 so should be within specification . Any other ideas ?
    Going to try some Remington brass .
     
  6. rost495

    rost495 Well-Known Member

    Messages:
    222
    Joined:
    Nov 11, 2003
    brass thats too hard? Anneal a handful and see what happens.