Need precision reloading advice please

Klay23

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    I’m noticing an accuracy difference on paper between new brass and resized brass and trying to figure out the culprit. This is 223 Lapua brass and 69gr smk’s. New brass that has been expander mandreled and dechamfered/deburred shoots an .3” at 100. Once fired brass is double that plus some in some groups. I’m punching the primer, then annealing in my amp then resizing to .002 bump from the shoulder without the expander ball and then trimming to 1.75” and dechamfering etc and then expander mandreling the neck. I’m checking my bump with a Whidden bump gauge and it’s consistent. Yet the groups are doo doo. Any advice? Any thing to look into? I’m getting new brass shoulder at 1.4425-1.4430. Fired is 1.445-70. I’m also seating to the same depth from ogive.
     
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    straightshooter1

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    I take some case volume measurements to see if there's any significant difference. With 223's, it wouldn't take much of a difference in volumes to do something like that. I'm not saying this is what's actually a problem, but it's something that could be and I'd want to know if it is or isn't.
     
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    918v

    It’s not the primer!
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    Try this: size your brass to the same dimensions as new, then anneal. Then mandrel the necks and it will shoot as your new brass.
     
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    BLKWLFK9

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    Change your seating depth with fired/re-sized brass. Your bullet is now .003 closer to the lands with your sized brass than it was with virgin. I would seat your bullets .003 deeper and see where that goes. This is why it is best to FF all your brass before doing any real load workup.
     

    Klay23

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    I take some case volume measurements to see if there's any significant difference. With 223's, it wouldn't take much of a difference in volumes to do something like that. I'm not say this is what's actually a problem, but it's something that could and I'd want to know if it is or isn't.
    Not sure how to measure internal case volume?
     

    Klay23

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    Change your seating depth with fired/re-sized brass. Your bullet is now .003 closer to the lands with your sized brass than it was with virgin. I would seat your bullets .003 deeper and see where that goes. This is why it is best to FF all your brass before doing any real load workup.
    Hmmmm…. I see your point with the brass growing…. But isn’t trimming taking care of this? Just trying to understand
     

    Klay23

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    No do it before. Basically what you’re doing is what the factory did.
    So, clean, deprime, size to same new dimension, trim/deburr/dechamfer, anneal and then expander mandrel, reprime and load …. Ok, I can do this
     

    Old Man with Gun

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    I would suspect neck tension. Try skipping the anealer from once fired and see if your groups are better.
     

    straightshooter1

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    Not sure how to measure internal case volume?
    1. Insert spent primers backwards into the primer pockets.

    2. If you have a simple digital scale like Frankford Arsenal's DS-750, you set the empty case on the scale and zero it.

    3 Using a little squirt bottle or some kind of eye dropper like devise, fill the case with water until it's level with the mouth. Usually, you'll want the water to form a little bit of a dome, then wick the water level with a tip or edge of a little piece of paper towel. Using a light source to get a reflection off the surface of the water enables you to easily see if the water is actually level.

    4. Record the weight

    5. Go on to the next case, zeroing the scale again before filling.

    It's not hard to do; just takes a little time.

    Case volume measurement is universally understood as the weight of H2O filled to the top of the case.

    BTW: don't compare virgin brass volume or sized case volume to fire case volume. They'll all be different. What you want is fired case volumes that have been trimmed to the same length for a good comparison.
     
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    Old Man with Gun

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    You Don’t think annealing and expander mandrel wouldnt be more consistent?
    I think how soft the neck is may have changed, doesn't matter if size is the same.

    I would look at Chronograph from both. If velocity / SD changed it is volume, seating depth or neck tension. I think the first two are less likely.

    You do not need to aneal once fired brass, skip the step and see if it resolves just as a test.

    You could also FL resize and aneal virgin brass and see if groups change as another test.

    Load development should be on once fired brass not virgin. You will never be able to get fired brass to act exactly like virgin.
     
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    briang7511

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    do you have a chronograph? knowing the speed difference between these 2 differences may help show the volume difference. you dont mention if this is a bolt or gas gun. also agree with annealing less, maybe after 2 or 3 firings. What powder and how much are you using?
     
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    Klay23

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    do you have a chronograph? knowing the speed difference between these 2 differences may help show the volume difference. you dont mention if this is a bolt or gas gun. also agree with annealing less, maybe after 2 or 3 firings. What powder and how much are you using?
    I have a LabRadar. I’ll bring it out next time I’m out and get some more data. I need to look at the dope book and see what the numbers were last time I was out. This is a bolt gun. Varget powder 24.3gr.
     

    Old Man with Gun

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    My take on volume is that every round gets fire formed to the chamber. So, when measuring case volume what you are looking for is a difference caused by the brass in terms of different wall thickness and such. Lapua is very consistent so I'm guessing if you measure once fired and twice fired from the gun they are the same.

    Measuring processed brass and virgin brass doesn't do much because they are not sized in the same way.

    There have been a bunch of tests of FL resize vs just bumping the fire formed shoulder. They do not imply that the sizing method changes chamber volume.
     

    BLKWLFK9

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    Where did your .003 come from? My numbers or what you’ve experienced?

    Your fired dimensions + .002 bump VS your virgin measurements you posted.

    Brass grew .005, then you bumped .002, leaving a .003 difference.
     
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    straightshooter1

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    My take on volume is that every round gets fire formed to the chamber. So, when measuring case volume what you are looking for is a difference caused by the brass in terms of different wall thickness and such. Lapua is very consistent so I'm guessing if you measure once fired and twice fired from the gun they are the same.

    Measuring processed brass and virgin brass doesn't do much because they are not sized in the same way.

    There have been a bunch of tests of FL resize vs just bumping the fire formed shoulder. They do not imply that the sizing method changes chamber volume.
    Yes, Lapua brass tends to be very consistent with volume, which is a main function of case wall thickness. Even as consistent as Lapua tends to be, I'd never assume one lot of brass is the same as another and why I'd want to check it out.
     

    Old Man with Gun

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    Yes, Lapua brass tends to be very consistent with volume, which is a main function of case wall thickness. Even as consistent as Lapua tends to be, I'd never assume one lot of brass is the same as another and why I'd want to check it out.
    That is fair, but since the virgin brass shot well, I don't think brass inconsistencies are likely.
     

    Near miss

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    1. Insert spent primers backwards into the primer pockets.

    2. If you have a simple digital scale like Frankford Arsenal's DS-750, you set the empty case on the scale and zero it.

    3 Using a little squirt bottle or some kind of eye dropper like devise, fill the case with water until it's level with the mouth. Usually, you'll want the water to form a little bit of a dome, then wick the water level with a tip or edge of a little piece of paper towel. Using a light source to get a reflection off the surface of the water enables you to easily see if the water is actually level.

    4. Record the weight

    5. Go on to the next case, zeroing the scale again before filling.

    It's not hard to do; just takes a little time.

    Case volume measurement is universally understood as the weight of H2O filled to the top of the case.

    BTW: don't compare virgin brass volume or sized case volume to fire case volume. They'll all be different. What you want is fired case volumes that have been trimmed to the same length for a good comparison.
    I added just a tiny bit of dish washing soap to make the water more flat at the case mouth. It also prevents air bubbles from forming while filling the case.

    In regards to comparing the fill rate, the official volumes are reported probably for 1.76" brass so my guess is that a case of that length would give you the best universal comparison. (Say, you want to compare between manufacturers or input the volume to Gordons Reloading tool.)
     
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    918v

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    The reason 1x fired brass is shooting different is because it’s releasing the bullet differently. Either you restore the brass to factory or you rework the load in 1x brass.
     
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    Doom

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    I don't have an answer but I might be able to help you fix the issue and not go down a rabbit hole. The typical accuracy nodes in 223 are fairly narrow in terms of powder charge, often on the order of +/-0.1 grn of powder. Likewise any/all other changes can easily get you out of the node. You have an identified load and I would strongly recommend that you work up the load in your resized brass. It should be close to your new brass load. Do it using the same process you did for new brass.
     
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    Klay23

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    Made up a few loads for this issue and sizing the brass did help some. .4” groups but still not quite as tidy as new brass. Starting to wonder how much better I can actually do this.😂. I realize I am likely the weakest link in this equation.
     

    straightshooter1

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    Made up a few loads for this issue and sizing the brass did help some. .4” groups but still not quite as tidy as new brass. Starting to wonder how much better I can actually do this.😂. I realize I am likely the weakest link in this equation.
    The new brass likely has a tighter hold on the bullet, so maybe your gun likes more neck tension??? If you're getting .4" groups, you might give that a try by only changing this element of your loading to see if it makes any difference. It's not unusual for some guns to like more neck tension. So, if you're using .002 neck tension, then you might try .003 (if you've got the expander mandrel to do that).
     
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    Klay23

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    Get some 8208 xbr

    77SMK

    2.25 OAL

    23.2 grains

    Hit delete on this post.
    No go on the delete for now. I’m trying to gain wisdom from people who have been there and done that. I’m clearly not the only person to notice new brass vs fired brass and how different it can be. Loading isn’t terribly difficult, but loading very precisely is a different game that I’m trying my best do figure out. I appreciate every single response as it’s someone’s experience that may help me one day or today…
     

    pmclaine

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    Precision Reloader….

    image.jpg


    Precision .223

    image.jpg
     
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    pmclaine

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    Looks real good. I had that and then it left😂. If I come across some other powder like you mentioned I’ll give it a try. I have 77gr Bergers as well and they shoot well too but new brass and fired brass has me at the moment
    I do sort brass by head stamp but thats it.

    I don’t think the Rapid Trim is an Accurate Trim.

    Shit shoots good enough in my bolt 700 and .223.

    If you are a benchrester maybe you need something better but I do 300-400 at an easy pace and just about every shot does what it is told.
     

    Klay23

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    I do sort brass by head stamp but thats it.

    I don’t think the Rapid Trim is an Accurate Trim.

    Shit shoots good enough in my bolt 700 and .223.

    If you are a benchrester maybe you need something better but I do 300-400 at an easy pace and just about every shot does what it is told.
    That’s all I’m trying to do. And I’m quickly figuring out that paying very close attention to small details and etc etc etc make a difference
     

    straightshooter1

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    That’s all I’m trying to do. And I’m quickly figuring out that paying very close attention to small details and etc etc etc make a difference
    Yup, that's what it's all about.

    That's why many of us doing precision reloading are accused of having OCD. 🥴 ;)
     
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