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Taper Crimp Not Even Needed?

Discussion in 'Handloading and Reloading' started by vtail, Feb 12, 2013.

  1. vtail

    vtail Well-Known Member

    I've started loading some 40S&W and I'm concerned I was over taper crimping.

    So tonight, using a set of three Redding dies on a LNL, I seated a Montana Gold 180JHP to 1.125, and then started backing out the taper crimp until it would no longer pass the Plunk test into my barrel.

    To my surprise, I was able to entirely remove the taper crimp die and still pass the test. The seating die must be doing some crimping, but is it enough?

    It looks like all of the bell is removed, except for maybe a tiny bit at the end, but at this point, does it matter?

    For the record, I put the bullet against the bench and pushed on the back of the case as hard as I could and didn't budge the bullet.

    Should I even bother with the taper crimp die??
  2. mgmorden

    mgmorden Well-Known Member

    Virtually all seating dies have a "crimping" function built in. I started on Lee 4-die sets for handgun and always crimped as an extra step using the FCD, but the longer I've loaded I've become more and more of the opinion that a separate crimp step is completely unnecessary (and a time waster since I'm a single-stage loader).

    When you put in your seater, take a freshly sized case that hasn't been expanded. Raise it in the ram. Screw down the seater die until it contacts that case. Thats the point where the bell is removed. Asjust the seater plug as needed to get your desired seating depth but other than that you're good to go.
  3. rcmodel

    rcmodel Member in memoriam


    The taper crimp die IS the seating die.

    Adjust it to seat to the proper OAL, remove the case mouth bell, and Fuggedaboutit.

    The Taper-Crimp does not hold the bullet in place, and the more you make it crimp, the looser the case neck tension gets.

    It makes the case like a factory load again so it feeds right.
    Thats all it does.

    But you DO need to use it.

  4. Drail

    Drail Well-Known Member

    If you have sufficient case neck tension (which you do if you cannot press the bullet in by hand) then you do not really need hardly any crimp. Just flare as little as possible and remove any flare that will not allow the round to fall in and out of a chamber or gauge.
  5. Waywatcher

    Waywatcher Well-Known Member

    For my .40 reloads I taper crimp 0.001" and no more. They work perfectly!
  6. Bovice

    Bovice Well-Known Member

    That tiny little bit that is still belled DOES matter. Get rid of that or you'll have rounds that don't quite feed. That little edge will snag.
  7. vtail

    vtail Well-Known Member

    Wait, what?

    I'm not understanding this statement:

    "The taper crimp die IS the seating die."

    Do you mean I should attempt to adjust the seating die to remove ALL of the remaining bell, (which is almost nonexistant), and not even use the separate taper crimp die at all?
  8. Waywatcher

    Waywatcher Well-Known Member

    The taper crimp die has the seater plug already in it. The bell should be removed and verified to have been removed with a caliper.
  9. vtail

    vtail Well-Known Member

    My taper crimp die is hollow.

    My seater die has the seater plug in it. Whether it is capable of removing all of the remaining bell is yet to be seen.

    If not, I suppose I will have to use the taper crimp die as well. I know it can, as it was doing it before. I was just worried perhaps I was over doing it.

    This is really all academic as I have an open station on my LNL, so it's really no big deal to use the taper crimp die, I was just wondering if I really needed to use it at all.
  10. bds

    bds Well-Known Member

    Better QC check for neck tension is measuring the OALs before/after feeding the finished rounds from the magazine with the slide locked back then releasing the slide.

    If you have significant reduction in OAL, then you have neck tension issue.

    I used to do the same then saw reduction in OAL when they were fed from the magazine, which better duplicates the actual feeding/chambering action/pressure.
    Last edited: Feb 12, 2013
  11. 1SOW

    1SOW Well-Known Member

    You do need to remove the bell to have reliable feed.
  12. vtail

    vtail Well-Known Member

    Will do. That's a good idea.

    Thanks for the tip.
  13. vtail

    vtail Well-Known Member

    To totally remove the last little bit of bell, I had to screw the taper crimp almost all of the way down to the shell plate. Scared I may be overdoing it.

    May still be able to remove it with the seater die only. Will try it tomorrow.
    Last edited: Feb 12, 2013
  14. Lost Sheep

    Lost Sheep Well-Known Member

    Is everybody talking about jacketed brass (which tends to be just the size of the barrel, as opposed to lead which tends to be a little larger)?

    Lead bullets need a little bit more flare than jacketed or plated bullets in order to fit the bullet base into the case mouth. So, there is a little more flare to remove.

    If you have bullets with beveled bases and put them on the case mouth perfectly square, I can see where you might not have to remove the flare or might not even need any flare at all TO remove.

    In that case, you can probably get by without "taper crimping" your cases.

    No surprise at all.

    Lost Sheep
  15. GLOOB

    GLOOB Well-Known Member

    Sometimes it's true you don't need a crimp. Depends on your bullet, chamber, and flare. But it's still best to set the crimp ring on your seating die to where it at least touches the case mouth. This is so that the oddball long case that got more flare will get crimped, if not the rest of the batch.
  16. cfullgraf

    cfullgraf Well-Known Member

    Seating dies have a crimp ring built in. It is standard. I do not know of a seat die, particularly for handgun cartridges, that does not have a crimp ring machined into it.

    To set the seater die to seat and crimp, back the seater stem out and adjust the die body down to get the desired crimp on a case with the bullet seated. Then, adjust the seater stem to get the over all cartridge length.

    If you move the die body without moving the seater stem independently, your cartridge overall length will change. You can move only the seater stem and the crimp will not change while the cartridge overall length will.

    Some folks prefer to crimp in a separate step from seating so they have a crimp die. In this case, back the seater die body back so that the internal crimp ring does not touch the case. Adjust the seater stem to the desired overall length.

    Then, adjust the crimp die body to obtain the desired crimp.

    For semi-automatic hand guns, you should remove the mouth belling from the case for reliable feeding. As said, with jacketed bullets, it is quite possible to expand the mouth just enough so that crimping is not necessary.

    This is not possible with lead bullets. The lead bullets are soft and the case mouth will shave lead during seating if the mouth is not expanded enough.

    Everybody seems to be saying the same thing, but not very clearly.

    Hope this helps.
    Last edited: Feb 12, 2013
  17. Dodge DeBoulet

    Dodge DeBoulet Well-Known Member

    Adding just a little bit more clarity :D
  18. cfullgraf

    cfullgraf Well-Known Member

    Right, thanks
  19. jlear56

    jlear56 New Member

    Not trying to confuse the issue here but, I don't think my Dillon seating die crimps, If i do not run the seated round through the tapered crimp die, there is no way it will pass a chamber check!

    As a matter of fact the Redding Comp Seating die does not remove the crimp either. :confused:
  20. James2

    James2 Well-Known Member

    ^^^ This.

    You can adjust the seating die to also give you the necessary crimp, and seat and crimp in one step with one die.

    You can also set the seating die so that it does not crimp and crimp in another step with a crimp die. I have heard arguments for both methods, but for me it works just fine to crimp and seat in one operation with the seat die. Your mileage may vary, but whichever method you use, it is important to adjust the dies properly. If you are going to use both dies, make sure the seat die is not crimping so the crimp will be done in the crimp die.

    If you take the seating stem out of the seat die and look into it you will be able to see the crimp ring. When adjusting the die, put a casing in the shell holder (no bullet) and run it up full stroke, then turn the die in until you feel some resistance. This is where the brass hits the crimp ring. Now if you don't want to crimp, back it off half a turn. If you do want to crimp, with a charged casing add a bullet and adjust the COAL, back off your seating stem while playing with the crimp, then play with the crimp. You get more crimp by turning the die in further. Once your crimp is right, with the ram full up turn the seating stem in to hit the bullet. Now you can seat and crimp in one operation.

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