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Taper Crimp Die Sctatching Cases

Discussion in 'Reloading' started by Jim, Nov 28, 2011.


  1. Jim

    Jim
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    Over the years I've loaded several thousand 9mm 115 gr jacketed bullets on my Dillon 650. I use a very mild taper crimp, just enough to take out the slight belling I use. Within the last thousand rds, I've started getting scratches near the mouth of the case where the taper crimp die squeezes out the belling.

    The scratches are showing up in the first 3/32" by the mouth, they are not huge but deep and sharp enough I think they will eventually start cracks in the brass.

    I used a .45 stainless brush in a straight cleaning rod, chucked in an electic drill, to clean out the crimping die. That solved the problem for only about 50 rds, now it's happening again.

    What's going on that I loaded about 5,000 rds in previous years without the scratches, now it looks like I need to clean the crimping die every 50 rds or so to prevent scratching?
     

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  2. kjm1016

    kjm1016
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    The answer is simple, buy a new die.
     

  3. Jim

    Jim
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    That might work, or might not; I've never heard of this problem before. I can clean up the die with the .45 stainless brush, and then it doesn't scratch for 50 rds. So something is getting in there to cause the scratches, that wasn't there for the previous 5k rds. Nothing else has changed in my reloading.

    BTW, I tried backing off the die even more to see what happens; the only way to prevent scratching is to back it off to the point that it doesn't even eliminate all of the belling.
     
  4. fredj338

    fredj338
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    Important info, who's dies? IF they are Dillon, just call them & have them send another. If Lee, maybe they'll back their product. It sounds like the die mat'l. is soft & ytou are getting embedded brass or bullet shavings. Do yo ubell the cae mouth prior to bullet seating? If not, you should.
     
  5. Jim

    Jim
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    Dillon dies.
    I called dillon, they recommended using a cleaning patch with valve grinding compound wrapped around the stainless brush. That should polish out any roughness which is causing brass shavings and allowing them to stick there.

    I'll give it a try.
     
  6. GioaJack

    GioaJack
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    Conifer Jack

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    There are several different grits of lapping compound, use the fine grit. If you're worried about taking off too much material use jewelers rouge.

    You'll probably get more uniform results by using a cylindrical buffing wheel on the end of a flexible Dremel extension so you can get inside the die.


    Jack