Powder Marks on case

Discussion in 'Ammunition & Reloading' started by DukesDad, Jul 19, 2012.

  1. DukesDad

    DukesDad New Member

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    I just started reloading and after my first range session with my first reloads I've got some "interesting" powder marks on the neck of the case.
    My load is;
    .30-06
    165gr. Hornady SST
    49.5 gr. IMR 4895

    All the loads are once fired brass out of my Savage Edge.
    After firing I checked all the cases and each one has two U-shaped powder "burns" that extend the length of the neck and meet up at the mouth of the case.
    My question is, are my loads correct, are the "burn" marks an indicator of something I need to be concerned with or is it just a side effect of my particular load?
    Any info would be greatly appreciated. Thanks
     
  2. The_Kid

    The_Kid New Member

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    Some loads take a instant for the neck to seal completely and there will be that carbon deposit. That ring itself is nothing to worry about.

    If you aren't seeing overpressure signs I would venture to tell you that your load isn't incorrect.

    So we know we are on the same page, I have a video of a sooted 30-06 case.
    [ame="http://youtu.be/MB1BARLZzFs"]http://youtu.be/MB1BARLZzFs[/ame]
     
    Last edited: Jul 19, 2012

  3. steve4102

    steve4102 New Member

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    You can try and increase your powder charge to see if it clears up. You are right about at the Min for your bullet/powder combo, bump it up and see.
     
  4. DukesDad

    DukesDad New Member

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    The case in the video is virtually identical to mine. I'm not sure if I understood your post exactlly, does that mean my load is fine, or the charge is a little light? I'm not showing any signs of overpressure.
    thanks very much for the video, that helped immensely.
     
  5. oldpapps

    oldpapps New Member

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    It could be.......

    First the least likely. The rifle's chamber/throat is screwed up. If the factory loads didn't leave the soot, I would scratch this one off the list.

    Two options in one. Too little pressure and the case mouth doesn't get pushed out (fast enough) to seal the escaping gasses and some soot gets on the outside of the neck. Too much pressure and gasses try to escape back in the chamber and some soot gets on the outside of the neck.

    A quick glance at Hodgdon's on line loading data shows something similar to your loading. One min/max is 44.4 to 47.8. Your loading of 49.5 grains would be high. But, a second listing is min/max of 49.0 to 52.0. Your 49.2 is in line with this one.

    Now to the real question/s.
    Are any pressure signs being exhibited (flattened primers, hard extraction, etc.)?
    Does this loading meet with your desired uses for it?
    How accurate is this load?

    If your answers to the above is: NO, YES, and ACCEPTABLE. Don't let it trouble you. If these questions don't match, change your loading.
     
  6. robocop10mm

    robocop10mm Lifetime Supporting Member Lifetime Supporter

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    Aneal the case necks and this will go away. Brass "work hardens". It gets harder everytime it is shot and resized. I aneal all rifle case every time (excessive), but I am more than a little OCD. Anealing will return the necks to the malleable state that is needed to seal off properly.
     
  7. steve4102

    steve4102 New Member

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    This data is for the Hornady GMX an all copper bullet, the SST is a lead core bullet. When data for the exact bullet cannot be found, it's best to use data of same weight of similar construction. In other words, do not use lead core bullet data with solid copper bullets and verse-visa.
     
  8. oldpapps

    oldpapps New Member

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    I beg your pass, I was only looking at bullet weight and the charge. I fully agree with sticking with similar bullet design and construction when building a load. I just didn't look that deep.
     
  9. DukesDad

    DukesDad New Member

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    Does anybody have a hornady reloading manual? If so does it give load info for the 165 sst? Because I've checked other spots online and my load should be fine, but on further inspection of the cases I am getting a slight amount of primer flattening. Should I scrap the load? If so any recommendations on how to salvage 40 rounds of lightly crimped brass and quality bullets. Obviously I need to do a small test batch for load development, not fill a box.
     
  10. steve4102

    steve4102 New Member

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    Hornady #7 has data for their 165gr SST, but no IMR 4895.

    Reading primers is about as accurate as reading Tea leaves. Flattened primers can be caused by many things, high pressure being only one of them. Your load is at the bottom end according to Hodgdon, so I highly doubt you have a high pressure situation. More likely your brass has been sized to much causing a slight headspace issue. With excess headspace the primer can back out, then the case head is slammed back intro the bolt face flattening the primer, giving the false impression of a high pressure load.
     
  11. gunnut07

    gunnut07 New Member

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    According to Hodgdons web site you are running .5gr above the starting load. I would load at 50 to 51 gr of 4895 and see how it goes. I would do a ladder test and see about accuracy and case neck sooting.

    The sooting around the neck is from a load that is on the lower side of the pressure curve. It is not producing enough pressure in the beginning to expand the brass case neck all the way and seal the chamber. Nothing serious just a little extra time in the cleaner. I would look at varget or IMR 4064. I love 4064 myself.
     
  12. The_Kid

    The_Kid New Member

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    A "slight amount of primer flattening" is normal. Cratered primers are a sign of over pressure.
    Here are two cases shot from my US Model of 1917, 30-06.
    [​IMG]

    The cratered primer on the right is, (as I see it,) borderline overpressure. That is a slight cratered primer, I've seen a lot worse.
    If your cases are flat on the edges like on the right, but do not show the raised edges of a crater; I would not consider them overpressure.

    I'd like to revise the last sentence.
    If your cases are flat on the edges like on the right, but do not show the raised edges of a crater, and you find no other overpressure signs; I would not consider them overpressure.

    This is a pic of an overpressure case with no cratering. The ejector mark on the face, along with the extremely flattened primer; are the overpressure signs in that instance.
    [​IMG]
     
    Last edited: Jul 20, 2012
  13. KeysKelly

    KeysKelly New Member

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    My first guess is dirty powder. I only load handgun ammo and use Unique Powder because it is pretty universal and I can find several different loads for just about any handgun caliber and bullet weight made. Unique is a very dirty powder though and leaves burn marks on most of my cases. I just figure that's what my tumbler is for.