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Thread: 30-378 Weatherby Magnum shells deformed

  1. #1
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    Default 30-378 Weatherby Magnum shells deformed

    Had a friend describe a problem regarding some recently reloaded 30-378 bullets and I wanted to run it by the collective brain trust to verify my suspicion. I didn't get to ask him all of the details, but here is what I'm able to pass on-
    He's new to reloading and I think this was his first attempt at reloading. As described to me, he loaded 20 rounds using new brass and a moderate powder charge using a manual he had. (powder charge) He didn't tell me what kind/weight bullet he used. In the course of shooting the first few, he noticed creases/deformities running from the neck back down the base of the shell. There were three of these ridges/deformations on each shells he shot. He stopped shooting the reloads and tried again using new factory rounds. All of the factory rounds were fine with no deformations on the brass.

    Question: does he have a head space issue or could he have possibly overloaded/ used the wrong powder to cause an overpressure issue ??

  2. #2

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    Hard to guess from the description. Can you get pics?

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    Default

    It's hard to tell without looking at the ammo. However, I have seen brass with indentation or shallow grooves (dents) around the neck and shoulder because of excessive lubricant use.

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    Quote Originally Posted by Polardude View Post
    In the course of shooting the first few, he noticed creases/deformities running from the neck back down the base of the shell. There were three of these ridges/deformations on each shells he shot. He stopped shooting the reloads and tried again using new factory rounds. All of the factory rounds were fine with no deformations on the brass.

    Question: does he have a head space issue or could he have possibly overloaded/ used the wrong powder to cause an overpressure issue ??

    I don't know without looking at the brass. Doesn't sound like high pressure or headspace problem. Probably die adjustment problem or debris in the chamber (cleaning patch threads) or defective brass. Did the rounds look good before firing? Can we see a picture of the fired brass?
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    Default dented shells

    We're both on the slope right now. Will post a picture ASAP, probably + - 10 days from now. Thanks for the peplies, I'm anxious to see what you think

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    Default picture of shell

    Hopefully, I can attach a picture of the damaged shell that arrived yesterday. The quality isn't the best but it should depict the extent of creasing. There are 3 equal length creases on each of the shells he shot.
    I asked a few more questions regarding his reloads.
    My friend claims brass was once-fired weatherby, trimmed to factory specs. he measured the overall finished length to verify factory specs after reloading. Keep in mind that he followed up the session with factory rounds and they shot fine in the same rifle.
    Any ideas?
    Attached Thumbnails Attached Thumbnails scotts shell_gif.jpg  

  7. #7

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    Has that case been cleaned after firing? If it was blackened, I'd suspect the dents were the result of "blow-back" or whatever you want to call it. That's what can happen with severely reduced loads and slow powders, when gases get out of the case and go backwards before pressures have built enough to swell or obturate the case to a tight chamber fit. What were his charges and what powder was he using?

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    New member George's Avatar
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    Default Yikes

    Something is most assuredly wrong! You might suggest to him not to shoot any more of those. I've seen buckled cases- it's not too common- but that is the worst I've seen. Given the nature of the 30-378 over bore configuration along with some other unknowns about the reloading techniques used, I'd also suggest to your friend to get some more help in sorting the problem out before proceeding. BrownBears's guess as to the cause is as good as any.

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    + 1 for BrownBear. Not making enough pressure to expand the case and seal the chamber.

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    That looks to me like over lubing the case when it was run into the die.

    I think we've all seen this before, I don't believe the ctg was fired in a rifle chamber regardless of what this fellow told you.

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    Default I'm with big Al

    Those cases are way to shiny and the indents are behind the sholder. A better picture would help. What exactly the load was would also be of help

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    Yup, over-lubed and in a big way.
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  13. #13

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    If it was happening during reloading, I'd agree with overlube. But according to the original post, the dents/creases are happening upon firing. Back to my point about blowby, and my question about cleaning the cases before the photo was taken.

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    Default I'll ask him

    I'll ask him again about the load. I believe I asked him initially, and he said he'd have to check his notes at home. I'll post his data ASAP.

    If it was happening during reloading, I'd agree with overlube. But according to the original post, the dents/creases are happening upon firing. Back to my point about blowby, and my question about cleaning the cases before the photo was taken.[/QUOTE]

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    Default Gas dents..

    This appears to be the result of gas dents caused as BrownBear said by expanding gases getting past the case neck and back flushing into the chamber around the case body. These will normally leave a black sooty covering on the case but has been cleaned I suppose. Lube dents are usually confined to the shoulder of a case and are iron out by the firing of the round. The is caused by too light of a load and it could lead to severe damage to gun and shooter. This 30-378 is a greatly over bore case and needs to be loaded with the slowest burning powder available. RL-25, IMR 7828, H1000 or Retumbo. The case cannot be filled and only the bulkiest and slowest of powders can be used.

    At first glance it looks like disaster waiting to happen. Is a source for good load date being consulted?
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    Gentlemen,

    I would like to point out the gas pressures within the barrel, at any point, will be the same. There will be no pressure differential that would allow the pressure on the outside of the case, to be greater than the pressure on the inside of the case while it is in the chamber.

    The idea there could be entrapped gas, like a bubble, is imaginative. If there could be such a thing, and I do not believe there could be, this bubble would have a much lower pressure than at peak, which would be up over 60kpsi. It would be instantly ironed out, the gas being forced out from between the case and chamber wall.

    The fellow is new to reloading. The first post does not state whether or not the fellow noticed the cases before or after being fired, only that he saw them in the course of shooting. Also, there has been no further updates on this initial post.
    Great spirits have always found violent opposition from mediocre minds. The latter cannot understand it when a man does not thoughtlessly submit to hereditary prejudices but honestly and courageously uses his intelligence. Albert Einstein

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  17. #17

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    Been there, done that on blowby with over- capacity cases such as this.

    The point is that gas flows back past the case when the bullet first hits the rifling but before the case obturates. Due to bullet resistance in the bore as the gases start to expand and pressures first begin to build, the path of least resistance is briefly back past the case rather than pushing the bullet down the bore. As ignition continues and the bullet begins to move down the barrel, the case obturates enough to direct all the gases down the barrel.

    Doesn't have a fig to do with differencial pressures inside and outside the case. Or and apple or an orange for that matter. Purely a question of direction of gas flow before obturation.

    The 257 Weatherby was a real stinker on this account in its early day when reloaders were empirically testing surplus powders slower than 4831. Weatherby even recalled one batch of ammo due to blowback from underpressure loads combined with some out-of-spec hard cases.. Probably paid for a new eye here and there, as well as a few ruined rifles. They certainly weren't saying much about it. Murphy is dead right. It's a dangerous condition.

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    Default same dents

    When I began reloading the only thing I had was a 300 Savage. It had a very similar profile, ie very short neck and very sharp sholder. I made dents in those first cases that looked identical these dents. Not to say that these were made that way but that is how I made similar dents.

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    Default same dents

    I should add that I made those dents by over lubing the cases.

  20. #20

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    Yup. Made them myself with overlube. But overlube dents are on the shoulder, and there's just about no way to do that without affecting the shoulder. They also disappear on firing.

    These dents are on the body of the case. And they appeared after firing. I've done that, too. Not coincidentally with overbore rounds and low pressures. Those appear AFTER firing, as happened here.

    Tempest in a teapot. Consult a reloading manual. Use recommended loads. Follow directions. Poof! The dents disappear and you save a gun, and maybe even an eye.

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