21 century expander mandrel

bergcomp

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Just an opinion about reloading process for Lapua .308, Iam using Forster FL die honed to .334, after that separately 21 century expander mandrel..
Does anybody use expander twice ? I noticed that after springback if I use expander again , through some necks it goes harder than others, I guess it has to do with springback ?
 

straightshooter1

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When I FL size, I use my Forster FL sizing die without expander ball, then run the expander mandrel through it . . . only once. I do anneal after every firing, so that helps a lot with regards to springback. The only time I have occasion to run an expander mandrel twice is when I'm turning necks where often, after some time (like 24 hrs or so) the neck will have contracted to much making the neck too tight on the neck turning mandrel. For seating after sizing, once is enough for me.
 

Nimothy

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    So I talked to fella once an f class guy he seemed pretty knowledgeable, he mandrels his turned it in the shell holder and sent it through twice. And paused at the up stroke both times, seemed excessive but he had a wild rifle that was making tiny groups at 300yrds
     

    straightshooter1

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    So I talked to fella once an f class guy he seemed pretty knowledgeable, he mandrels his turned it in the shell holder and sent it through twice. And paused at the up stroke both times, seemed excessive but he had a wild rifle that was making tiny groups at 300yrds

    I've found the dwell time (the "pause" on the stroke) is very helpful in reducing some of the springback and helps get more consistent results.
     

    bergcomp

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    So I talked to fella once an f class guy he seemed pretty knowledgeable, he mandrels his turned it in the shell holder and sent it through twice. And paused at the up stroke both times, seemed excessive but he had a wild rifle that was making tiny groups at 300yrds
    So nothing wrong can do to necks ? than size them again on .001 under bullet diameter with expander and probably will springback again but not too much as first time, they are fired once so I didnt annel , I dont have concentricity tool at the moment, but somethimes I notice that runout is reduced if I sized .337 expanded neck again with FL honed .334 and than expand back .337, less runout show
     

    bergcomp

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    So I talked to fella once an f class guy he seemed pretty knowledgeable, he mandrels his turned it in the shell holder and sent it through twice. And paused at the up stroke both times, seemed excessive but he had a wild rifle that was making tiny groups at 300yrds
    but pulls them through expander twice at once or takes a break for day two and than second time ?
     

    Nimothy

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    but pulls them through expander twice at once or takes a break for day two and than second time ?
    I think what he meant was two press strokes per piece of brass. With an expander mandrel, I’m assuming he Takes the expander button out of his dies. Another thing, you said you didn’t anneal because they are only once fired. If your looking for consistency don’t you think the same exact cases prep should be done everytime? Just my .02
     

    bergcomp

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    I think what he meant was two press strokes per piece of brass. With an expander mandrel, I’m assuming he Takes the expander button out of his dies. Another thing, you said you didn’t anneal because they are only once fired. If your looking for consistency don’t you think the same exact cases prep should be done everytime? Just my .02
    I got finally concentricity gauge so I did experiment, Check after fired, most of the cases measured 0.0005 runout, max 0.001, after sized with Forster honed die .334, 0.001" to max 0.002", than I pulled expander through to .337, same reading max .002", but If I sized them again to .334 with Forster, so that is second time sized I get less runout, +-.0005"
    After seating bullet with Forster Mic die, same reading .0005, max .001", I think thats ok up to 600 meters, I'm not shooting any further anyway
     

    padom

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    I got finally concentricity gauge so I did experiment, Check after fired, most of the cases measured 0.0005 runout, max 0.001, after sized with Forster honed die .334, 0.001" to max 0.002", than I pulled expander through to .337, same reading max .002", but If I sized them again to .334 with Forster, so that is second time sized I get less runout, +-.0005"
    After seating bullet with Forster Mic die, same reading .0005, max .001", I think thats ok up to 600 meters, I'm not shooting any further anyway

    OK to 600meters? low. you arent going to get better than that... A acceptable runout is .003-.005" . You are half that or less. You arent going to see that on paper even to 1000yd.

    You have someting else going on.... Are you looking for .001 neck tension or .002 neck tension. 21st Expander only gives .001 neck tension. Most of use their Turning mandrel from 21st that gives .002 neck tension... What is your fired case measuring? what is your loaded round neck measuring?
     

    padom

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    That is correct, those are new they just started carrying. But if you go to the specific turning mandrel page for the TiN and Black Nitride turning mandrels those are .002 neck tension turning mandrels. I was asking him which ones he has
     

    whatsupdoc

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    Just an opinion about reloading process for Lapua .308, Iam using Forster FL die honed to .334, after that separately 21 century expander mandrel..
    Does anybody use expander twice ? I noticed that after springback if I use expander again , through some necks it goes harder than others, I guess it has to do with springback ?


    Depending on the brass I push the mandrel into the neck twice, I get better bullet seating depth consistency doing this.
    Also if you have a doughnut at the shoulder neck junction of the case this usually helps Iron out the doughnut.
     

    bergcomp

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    OK to 600meters? low. you arent going to get better than that... A acceptable runout is .003-.005" . You are half that or less. You arent going to see that on paper even to 1000yd.

    You have someting else going on.... Are you looking for .001 neck tension or .002 neck tension. 21st Expander only gives .001 neck tension. Most of use their Turning mandrel from 21st that gives .002 neck tension... What is your fired case measuring? what is your loaded round neck measuring?
    I know, .001" tension, after springback, maybe .0015, thats what I was looking for, we will se on paper whats going on with all that at 600 meters
    Image below is 320 meters( 350yards +-)
    Depending on the brass I push the mandrel into the neck twice, I get better bullet seating depth consistency doing this.
    Also if you have a doughnut at the shoulder neck junction of the case this usually helps Iron out the doughnut.
    That's what I thought ;)
     

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    Sebrock

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    So I have two procedures - one for brass prepped to be turned and one for already turned brass. 6.5 Creedmoor. Non of the dies have expander balls in them.

    For brass to be prepped - I used a Whidden FS (non bushing die) which coincidentally is the same as the bushing I use for turned necks - so its pretty aggressive at getting the imperfections to the outside of the necks. I size, use an expander mandrel at .001 below bullet diameter (seems to be the preference for neck turning), turn the necks, size again and then use a mandrel at .002 minus bullet diameter. Then I trim, chamfer, debur. I do it on a turret and have two expander dies so not so time intense and I only do this once in the case life. With good case, I end up at or below .001 of TIR at the neck with bullet seated- uniform wall thickness of course.

    After the brass is fired I use my Whidden Full Size Bushing die at loaded round diameter minus .002 and then use a mandrel at .002 minus bullet diameter and then a second at minus .001 bullet diameter. This get me consistently at .001 TIR or less.

    The caveat is that you have to start with good brass obviously.
     

    mbeavers1

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    I know, .001" tension, after springback, maybe .0015, thats what I was looking for, we will se on paper whats going on with all that at 600 meters
    Image below is 320 meters( 350yards +-)

    That's what I thought ;)
    So looks to me like it's shooting pretty well if that's 350 yds, that is about a 1" group...like 0.35ish MOA.

    What do your MVs look like (SD and ES)?
     

    Dthomas3523

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    Feeling different types of resistance in a mandrel can also be friction related.

    Just like you can get two different seating pressures from cases with the same ID when one has lube and the other doesn’t.

    Seating a bullet and pushing a mandrel is basically the same thing.
     

    mr.quick

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    Feeling different types of resistance in a mandrel can also be friction related.

    Just like you can get two different seating pressures from cases with the same ID when one has lube and the other doesn’t.

    Seating a bullet and pushing a mandrel is basically the same thing.
    that is why I lube before putting it through the mandrel , then lube again to seat my bullet. 9 out of 10 come out with 3 lbs give or take , when seating my bullet. 44lbs average seating pressure.
     

    ICU22250

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    I am new to the mandrel thing, but I have been running my mandrel into the case 3 times, once then turn a little, then same thing 2 more times. I graphite the neck real good before hand of every case and this has tightened my groups substantially.. This was going from only using the mandrel once, which may be overkill, you could probably get by with 2 times.. This was with Virgin Lapua brass and the L.E. Wilson mandrel and die, maybe it was just my luck though, I don't claim to be an expert..
     

    Krob95

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    What type of lube are you guys using on your case necks with the mandrels? Just got one for my 6BRA from 21st century.
     

    Krob95

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    How are you getting into the case neck? Just a bore mop?
     

    GMZ

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    Krob95

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    Thanks man. Ordered some. Will lanolin work for the time being until it shows up?