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.223 sizing die-expansion problems

cwinncwinn Member Posts: 1,223 ✭✭
My new RCBS small base .223 dies are not expanding the case neck enough to accept .224" dia standard hornady 55 grain bullets. I adjusted the dies so they were slightly cammed-over (with decapping pin extended about 3/8" below die), and everything feels fine I think.

Even though the expander ball measures .222 with my calipers, even after passing back out of the neck it only expands the neck to around .216. This doesnt allow the bullets to seat, and my first batch resulted in moderate jacket shaving.

Though they fired fine, it made the loading process extremely difficult and resulted in some damaged cases and bullets.

I searched online and on RCBS website but had no luck. What gives?


  • charliemeyer007charliemeyer007 Member Posts: 7,348 ✭✭✭
    edited November -1
    Is the case mouth champhered? I apply a very thin coat of Lee sizing compound inside the neck with a q-tip before sizing. Try some other brand of brass. Maybe the ball is undersized,, got any other .224 dies to just push the cases into to expand the neck?
  • dcs shootersdcs shooters Member Posts: 10,969
    edited November -1
    A call to 800-533-5000 will get you an answer.
    It sounds like your brass is springing back too much. Are you lubing the inside of the neck before sizing [?] I use a spray lube on mine and it gets in and outside both. What brand brass do you have [?]
  • MobuckMobuck Member Posts: 12,764 ✭✭✭✭
    edited November -1
    I vote for insufficient chamfering f the case mouth. When I'm running sized and primed cases through my mongrel semiprogressive, I set the sizer w/o expander to do a 95% resize again. Although boattails work easier, I've loaded a pile of flatbases with very few problems as long as I start them straight.
  • nemesisenforcernemesisenforcer Member Posts: 10,513 ✭✭✭
    edited November -1
    Don't lube the inside of the case neck before sizing; they don't need it and powder can stick to the lube in that small of a neck.

    Try putting the expander ball down farther (closer to the bottom of the die.)

    If all else fails, get a neck sizer to run them through after full length sizing them.
  • NavybatNavybat Member Posts: 6,831 ✭✭✭
    edited November -1
    I would never lube the inside of the neck. My Lee dies work perfectly...perhaps your dies need adjustment? I concur that you should call RCBS and ask them. It might be a quick and/or simple fix.
  • JustCJustC Member Posts: 16,049 ✭✭✭
    edited November -1
    remove the decapping rod
    take a fired case in your hand
    insert the decapping rod into the case (as would happen inside the die)
    see if that expander ball is even close to going into the neck when the decapping pin bottoms out on the primer

    if that expander ball is far away from entering the case neck, then you have a decapping rod that is too long or won't allow the ball to enter the neck.
  • cwinncwinn Member Posts: 1,223 ✭✭
    edited November -1
    Hey guys

    I have not chamfered the cases yet, and did not apply any sizing lube for fear of (as mentioned) powder sticking, had been told that may happen.

    I'm using once fired Remington/UMC .223 brass. Unfortunately this is my only set of .223 dies at the moment.

    I already checked to see that the expander ball is indeed entering the case necks by removing it and hand checking. It appears that it is "springing" back into place....

    I'll take your advice and try to call RCBS today and let you all know what I find out.

    Thanks everybody
  • cwinncwinn Member Posts: 1,223 ✭✭
    edited November -1
    Finally talked to RCBS customer service (very friendly and helpful by the way).

    The woman I spoke with was very knowledgable and says I need to be chamfering the case neck a little prior to seating the bullet.
    She said there is no need for a crimp after seating due to the neck tension created by this method.

    I'll post if I have further problems.
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