Bullet runout after salt bath annealing and seating

Discussion in 'Reloading' started by charliehorse27, May 18, 2019.


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  1. charliehorse27

    charliehorse27 New Member

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    May 6, 2019
    Hey there everyone,

    I'm reloading for my dad's 270 using once-fired brass. Some of it was shot through his current rifle, some from his previous rifle.

    I recently forayed into the salt bath annealing arena. It was all annealed at 500 degrees C for 5 seconds after being once-fired. The first issues I noticed were afterwords in resizing. I used a Redding S series bushing die with the bushing and expander removed (in essence just a body die) so I could resize the neck with a Lee Collet die as his brass cases have not been neck turned. His chamber size is 2.049 so my goal was to set all the shoulders back to 2.047. Most of the brass (from his previous rifle) initially was around 2.052. When resizing, there was a fair bit of variance in the results. Most were in the range of 2.046-2.048 after being resized, but a handful of times it kicked brass out at 2.044 or less. All cases were lightly lubed with the Redding Imperial Die wax. Several times, thinking it was accumulation of lube in the die, I wiped it out but it still randomly occurred.

    I test seated a handful of bullets to check the bullet tension produced by the Lee Collet die. I am getting a tremendous amount of runout after seating. Case runout after the Lee Collet die has all been .002 or less. After seating the bullets using a RCBS comp seater die, I'm getting runout anywhere between .005-.01, which is unacceptable for me. I've tried using a standard RCBS seater die, with a little better results, but not much. I also tried sizing some of the case necks with the Redding S series die with the bushing in place, but the seating results are the same.

    The bullets seat easily, if not too easily, so I'm guessing neck tension needs to be adjusted. Is this symptomatic of over-annealed brass...? Getting slightly pushed around when the bullet is seated? This was slightly less than the recommended temp for salt bath annealing.

    Any advice or help would be appreciated. Thanks in advance.
     
  2. ar10ar15man

    ar10ar15man Well-Known Member

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    do you have any brass from the dame lot that is not annealed ?

    size and try seating, see what happens
     
  3. charliehorse27

    charliehorse27 New Member

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    Unfortunately, I don't have any other brass from that same lot that weren't all annealed and resized together. :/
     
  4. Silly_Ghillie

    Silly_Ghillie Well-Known Member

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    When you sized your brass, how much resistance did you get on the opening stroke (pulling the sizing ball back out of the neck)? did you feel more or less than usual? I have over cooked a few pieces of brass in my day and I have never had it feel any different on the seating, And I never check runout anyway.
    here, look at this. Maybe there is something on this thread that will help you out. https://www.longrangehunting.com/threads/over-annealing-cartridge-brass.122268/
     
  5. chesspunker

    chesspunker Well-Known Member

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    I returned an annealing machine after I ruined 50 beautiful form fired cases. Had same problem. Bad runout and horrible accuracy afterwards. Annealing is an art form and apparently I’m a horrible artist.

    My virgin brass shot better than 0.700” groups at 100 yards. My annealed brass went to 2” groups.
     
  6. Mc Fraser

    Mc Fraser Well-Known Member

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    Following, I'm in the same boat as the op
     
  7. Barrelnut

    Barrelnut Well-Known Member

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    You might have internal donuts after pushing the shoulder back so far on the brass fired from the other rifle with the longer chamber. Inside donuts can cause runout.
     
  8. charliehorse27

    charliehorse27 New Member

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    When I was sizing the brass initially, I did everything with the Redding as a body die and no expander, so I didn't get a chance to feel a change in resistance. I suspect some of the runout had to do with using the Lee collet sizing die for the neck, so I used a bushing die in the Redding Type S afterwords on all the pieces. The cases themselves varied between .001-.003 out of round after sizing. I don't know if this was due to the chamber of his previous rifle, or what. I'm also using Winchester brass in my 270 but normal case concentricity is usually less than .0015.

    Experimental seating with the cases post-Redding bushing sizing yielded concentricity between .003-.006. A little better, but still not great.

    I'm probably going to go out in the next couple of days and shoot a few cases set up with known producing loads and see if there's any attributable differences in accuracy or velocity after salt bath annealing. There was a bit of surprising resistance when seating the bullets, even after the annealing. The bushing die was set for .002 average neck tension.''

    Could this result if the case was from the larger chamber (2.052) and one of the ones resized to less than 2.044? I still have no idea what caused the seemingly random extra-long shoulder bump-backs.
     
  9. Barrelnut

    Barrelnut Well-Known Member

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    Yes, I happens more with sharp angled shoulders, like a WSM cartridge that has a 35% shoulder, I believe. Just the thickness of the brass can affect whether it doughnuts or not. I have had doughnut issues with Norma that I don't experience with Winchester at all. The more you push the shoulder back and the angle at the necks causes the brass that is pushed forward by resizing the case to pile up in the sharp angle at the shoulder neck junction. Think the 270 case is just 20% so not sure how quickly it would doughnut.
    This is the kind of issue that a doughnut can cause, if you are seating the boat-tail of the bullet below the shoulder neck junction.
    You can use a paper clip with a small sharp tip and run it down the neck at the shoulder neck junction. You can usually feel the doughnut. Might be able to see it with just a bright light.
     
  10. Fin-addictions

    Fin-addictions Active Member

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    Nov 26, 2014
    On the RCBS dies, are you using the bullet “window” feature, and is the bullet held in the die until you begin seating?