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Thread: Would appreciate your help with interpreting some ladder test data

  1. #1
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    Would appreciate your help with interpreting some ladder test data


    I made my first attempt at doing a load ladder test and generated some data with my 12FV 223 using a few different bullets and H322 powder.

    Powder charges were trickled and weighed on my trusty old RCBS 5-0-2 scale. I do question if this scale is adequate for doing this type of work.

    All rounds were loaded in full length sized Starline brass trimmed to 1.750" and using Winchester primers.

    Velocity measurements were taken with a Magnetospeed Sporter chronograph.

    In both tests, shots 2 and 3 were lower in velocity than shot 1. What's up with this? I saw the same thing a week before in data that I eventually discarded due to the chrono bayonet loosening and changing position mid test. Interesting that it repeated itself.

    My gut tells me that this data is questionable.

    Would anyone care to interpret the data and provide comments/opinions? I would appreciate any thoughts you may have on this.


    Hornady 53 grain V-Max loaded at 2.310" COL (0.040 off the lands)

    Gr H322 FPS
    22.2 3092
    22.4 3037
    22.6 3046
    22.8 3131
    23.0 3174
    23.2 3171
    23.4 3173
    23.6 3272
    23.8 3282
    24.0 3317


    Sierra Match King 52 gr BTHP loaded at 2.210" COL (0.020 off the lands)


    Gr H322 FPS
    22.5 3128
    22.7 3115
    22.9 3120
    23.1 3198
    23.3 3221
    23.5 3261
    23.7 3305
    23.9 3330
    24.1 3353
    24.3 3378


























  2. #2
    Basic Member Robinhood's Avatar
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    Your fears are real with your scale. To check it you can reweigh your charges multiple times. If it does not repeat precisely, It is suspect and need to be repaired or replaced. Heads up. Weighing accurate charges is either tedious or expensive for all that do it.
    The Dunning-Kruger effect is alive and well.

  3. #3
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    I think what you are probably witnessing is the effect of variation in velocity that you might expect from each load - only it is complicated by changing loads by 0.2 grains for each shot.

    If you loaded 10 rounds, all with the same charge, seating depth and trim length, you can expect 10-15 fps variation as a standard deviation and a max difference of 25 to 75 fps in extreme spread.
    Measuring variations, slight differences in the powder/primer interactions in each shot, and variations in how the chronograph reads the passage of the bullet across the sensors all contribute to the variations.
    If you get your reloading skills really tuned, you can get 5 to 7 fps SD and smaller extreme differences and that would include expected primer/powder ignition & burn variations shot to shot but you can't control everything.
    But the SD and max difference depends primarily on your reloading consistency.

    Shooting 10 loads with differences of 0.2 grains will experience the same kind of variations, shot to shot, only each load should be slightly faster than the last.
    QuickLOAD says the 0.2 grain increase will add 26 fps to the 53 gr V-Max loads. Your numbers show a 25 fps difference.
    QuickLOAD says the 0.2 grain increase will add 26 fps to the 52 gr SMK loads. Your numbers show a 27.8 fps difference.
    I would expect either the starting or ending velocities in your tests have a variation in different directions.

    Running a ladder with only one shot per charge adjustment means you are exposed to variations in a reading and any load in the sequence could be impacted. Your numbers could be explained by opposing variations making the differences be quite different than expected.
    If you shot your ladder again, with the same bullets, powder and charges, the variations may appear in different places.
    If you shot 10 shots at each charge and took the median and compared them, you might get a better idea of what's happening but that would be a pretty costly experiment.
    It is very hard to draw any conclusions from a single measurement that is subject to variations.

    Robinhood has hit the biggest potential source of variation - your scale.

    I would suggest you load 10 loads with exactly the same charge, the same trim length and the same seating depth and shoot them through your chronograph.
    If you have a high SD (over 10 -12 fps) and an extreme difference of 50 fps, what should be identical speed (with minimal variations) have relatively large deviations and you have some work to do on your reloading consistency.

    Your Magnetospeed shouldn't be a problem unless you have it mounted too far away from the center of the muzzle. I assume you have it set up correctly and it is stable.
    I measured my friends Magnetospeed when shooting through my Oehler 35P and they were in synch.
    The Magnetospeed measured about 8 fps faster since it was about 12 feet closer to the muzzle.
    There were still variations in individual measurements from shot to shot, but the averages between the two chronographs were very consistent.
    Last edited by CFJunkie; 06-05-2019 at 08:38 AM. Reason: Typos

  4. #4
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    CFJunkie,

    I will follow your suggestion and focus on a single charge weight to assess
    my overall capabilities.

    One question: What type of powder scale do you use or recommend for
    this precision work? I knew this day would come and am prepared to
    upgrade my scale if needed.

  5. #5
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    I think it is more to let you get a basis for your conclusions more than assessing your capabilities. It will give you an idea of what the inherent variation present in your loads. Then you can decide whether you want to take the effort to minimize them or live with the results you are getting. It all depends upon whether you are reloading for hunting or long range precision shooting.
    I load for accuracy and I also have a 12 FV .223 that shoots pretty well so far.
    I have a thread on this Ammunition and Reloading board that contains details on my loads, probably more detail than anyone except serious reloaders want to be bothered with.

    H322 is a good powder with lighter bullets like the 52 gr#1410 SMK and 53 grain V-Max. I have also had really good results with H335, CFE223 and VV N133 with light bullets.
    Your choice of bullets was right on. I also have had good results with the 53 gr SMK Flat base #1400 and 52 grain and 55 grain Berger #22408 and #22410, respectively with my 12 FV.
    If you choose to shoot some heavier bullets like 69 grain SMKs or TMKs, I would recommend a slower powder and I have had good results with IMR4166 Enduron, H4895, and N140. It may depend upon the rifle as each of my three .223s seem to like different powders, but all have different length barrels.

    As for scales, I have used a RCBS Chargemaster 1500 for almost 9 years and 46,000+ loads so I am not up on the latest scales.
    Obviously, I like the Chargemaster 1500 or I would have replaced it and while it was expensive at the time, I have gotten my use out of it.
    If you consider getting an electronic scale and or metering device, you need to let it warm up and then calibrate it before every use and make sure it is level.

    Everyone will have differing opinions, especially whether you want the scale to both measure and meter the powder.
    I think opinions may depend upon if you are comfortable with technology and the means of keeping them functioning correctly, or not.
    Experiences vary based upon what powder is being used.
    The large pellet extruded powders might cause some issues when metering and tend to clump up a bit when the humidity is high.
    Medium pellet powders don't seem to be as finicky and ball powders are no problem, but some complain that the small round ball powders spray around the scale as they meter because they are so light.
    Your bench can look like it is covered in fly scat when you're done loading with the light ball powders like H335 or CFE223.

  6. #6
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    Have you checked your scale with a Known weight piece, Weigh something youve weighed in the past and rezero scale.Have had rcbs scales in the past,minute partical of dust in pivot slot on balance beam,would clean w/small soft brush and see if that helps.Would also clean beam pivot points.Some times if it's 1 st shot out of cold clean barrel,or cold barrel,that first shot will be faster.Looks like you have a node at 23-23.6 H 322

  7. #7
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    Looking at your 53 V-Max chart, I see you've got a big ol' flat spot in your velocity between 23.0 and 23.6. That's a good thing, charge stability. Pick the middle charge and work with that and start moving the bullet forward .005 at a time.

    Personally I find IMR 3031 and the 53 gr V-Max to be an excellent combination with BR-4s or Fed 205M's. I get TINY groups out of two savage based rifles. But there's a ton of powders that'll do the job. H338 will give some impressive velocities with those bullets.

    Magnetospeed is pretty hard to beat without spending a lot more coin. I love mine, and wouldn't hesitate to recommend it. If yours is acting up, their customer service is nothing short of amazing.

    I am not the kind of marksman that can hit the eye of an eagle on a bet, so ladder tests are pretty useless to me. I can't separate shooting errors from charge variances on the target. So my go-to test is the OCW, three shots per charge weight, bullet jammed or jumped, your choice.

    YMMV.
    Banning a gun will not solve what is a mental health crisis inflamed by incendiary rhetoric on social and television media. The first amendment in this case is less precious and more likely the causal factor than the second amendment.

  8. #8
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    Quote Originally Posted by varget204 View Post
    Have you checked your scale with a Known weight piece, Weigh something youve weighed in the past and rezero scale.Have had rcbs scales in the past,minute partical of dust in pivot slot on balance beam,would clean w/small soft brush and see if that helps.Would also clean beam pivot points.Some times if it's 1 st shot out of cold clean barrel,or cold barrel,that first shot will be faster.Looks like you have a node at 23-23.6 H 322
    I need to get some calibration weights as I have never done this. I will also clean the pivot points.

  9. #9
    Basic Member Coyote_Hunter's Avatar
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    I've seen the same results with charges weighed on an electronic scale but in 0.5g increments. I don't let it worry me.

    My standard development process is one cartridge at each powder charge with 0.5g increments for rifle loads. I record the velocity and POI for each shot and look for a string that provides relatively consistent velocity increases and close to the same POI. When I find such a string I build more using a powder charge in the middle of the string and check them for velocity and accuracy. More often than not, I'm done.

  10. #10
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    I finally got back to the range this morning and took some velocity measurements on two different loads that I carefully assembled.

    53 gr V-Max
    23.2 gr H322
    WSR primer
    Case trim length: 1.750
    COL: 2.310
    10 shots
    Avg. Velocity: 3222
    Standard Deviation: 11
    Extreme Spread: 30
    Two group sizes were 0.58 and 0.67

    I am fairly pleased with the 53 gr V-Max result and have always done well with this bullet.


    52 gr Sierra Match King HPBT
    23.2 gr H322
    WSR primer
    Case trim length: 1.750
    COL: 2.210
    10 shots
    Avg. Velocity: 3249
    Standard Deviation: 19
    Extreme Spread: 70
    Two group sizes were 0.95 and 1.50

  11. #11
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    Quote Originally Posted by CFJunkie View Post
    I think it is more to let you get a basis for your conclusions more than assessing your capabilities. It will give you an idea of what the inherent variation present in your loads. Then you can decide whether you want to take the effort to minimize them or live with the results you are getting. It all depends upon whether you are reloading for hunting or long range precision shooting.
    I load for accuracy and I also have a 12 FV .223 that shoots pretty well so far.
    I have a thread on this Ammunition and Reloading board that contains details on my loads, probably more detail than anyone except serious reloaders want to be bothered with.

    H322 is a good powder with lighter bullets like the 52 gr#1410 SMK and 53 grain V-Max. I have also had really good results with H335, CFE223 and VV N133 with light bullets.
    Your choice of bullets was right on. I also have had good results with the 53 gr SMK Flat base #1400 and 52 grain and 55 grain Berger #22408 and #22410, respectively with my 12 FV.
    If you choose to shoot some heavier bullets like 69 grain SMKs or TMKs, I would recommend a slower powder and I have had good results with IMR4166 Enduron, H4895, and N140. It may depend upon the rifle as each of my three .223s seem to like different powders, but all have different length barrels.

    As for scales, I have used a RCBS Chargemaster 1500 for almost 9 years and 46,000+ loads so I am not up on the latest scales.
    Obviously, I like the Chargemaster 1500 or I would have replaced it and while it was expensive at the time, I have gotten my use out of it.
    If you consider getting an electronic scale and or metering device, you need to let it warm up and then calibrate it before every use and make sure it is level.

    Everyone will have differing opinions, especially whether you want the scale to both measure and meter the powder.
    I think opinions may depend upon if you are comfortable with technology and the means of keeping them functioning correctly, or not.
    Experiences vary based upon what powder is being used.
    The large pellet extruded powders might cause some issues when metering and tend to clump up a bit when the humidity is high.
    Medium pellet powders don't seem to be as finicky and ball powders are no problem, but some complain that the small round ball powders spray around the scale as they meter because they are so light.
    Your bench can look like it is covered in fly scat when you're done loading with the light ball powders like H335 or CFE223.
    I started looking at electronic scales and powder dispensers as an upgrade to my old 5-0-2 scale. For me, powder trickling and weighing has become a chore. Aside from the advantages of digital scaling, I was more intrigued by the potential for increasing my productivity at the bench. After reading many reviews and watching a number of videos, I purchased the RCBS Chargemaster Lite. It arrived yesterday and I immediately put it to use. I'm only 20 rounds into it but so far, I really like it.

  12. #12
    Basic Member Robinhood's Avatar
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    Quote Originally Posted by Bill2905 View Post
    I started looking at electronic scales and powder dispensers as an upgrade to my old 5-0-2 scale. For me, powder trickling and weighing has become a chore. Aside from the advantages of digital scaling, I was more intrigued by the potential for increasing my productivity at the bench. After reading many reviews and watching a number of videos, I purchased the RCBS Chargemaster Lite. It arrived yesterday and I immediately put it to use. I'm only 20 rounds into it but so far, I really like it.
    Please do a review
    The Dunning-Kruger effect is alive and well.

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    Quote Originally Posted by Robinhood View Post
    Please do a review
    Will do. I plan to make some rifle and handgun loads with different types of powders over the next week or so and will report back on my experience.

  14. #14
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    where is the TARGET???
    a LADDER is one step in load development.
    it does several things
    it helps identify nodes
    it should help id max load

    with no target you have no idea if two near velocities went anywhere near each other on the target.
    with a 10 shot ladder in 223, the steps should be 0.3 ( 1/100 of case volume)
    log each shots position on a target at the bench as you shoot them.
    circle the shots on the actual target in these grrups
    1.2
    123
    234
    345
    456
    567
    678
    789
    8910
    910
    you are looking for groups with very little elevation change, horizontal...you have to know what the wind was doing
    pick the 2 best, reshoot as 3 shot GROUPS in close to ideal conditions, pick the best and confirm with a 5 shot group.
    now play with oal to fine tune * this all works best if you start at the lands , not off, unless magazine length is an issue.

  15. #15
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    if i got that kind of variation in loading i would switch to a sling shot.
    that is not normal not to be expected in PRECISION LOADING.

    Quote Originally Posted by CFJunkie View Post
    If you loaded 10 rounds, all with the same charge, seating depth and trim length, you can expect 10-15 fps variation as a standard deviation and a max difference of 25 to 75 fps in extreme spread.
    Measuring variations, slight differences in the powder/primer interactions in each shot, and variations in how the chronograph reads the passage of the bullet across the sensors all contribute to the variations.
    .

  16. #16
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    mikeinco,

    I guess your 'precision reloading skills' and long term competitor mentality kept you from reading the sentence that followed that statement and recognizing that the OP never claimed to be a precision loader.

    The sentences that followed was:
    "
    If you get your reloading skills really tuned, you can get 5 to 7 fps SD and smaller extreme differences and that would include expected primer/powder ignition & burn variations shot to shot but you can't control everything.
    But the SD and max difference depends primarily on your reloading consistency."

    I am a bit disappointed that you, with all your knowledge of precision shooting espoused in your multiple posts on other threads, so easily assume that everyone has the same level of experience that you have or that they are equipped to follow or are even aware of the processes that you have apparently honed over the years.

    The OP asked for help in figuring out what his data means and the thread moved to variations in his approach.
    Maybe instead of consistently being a critic, you might offer some help on how the OP might improve to approach your "elite precision loading level".

  17. #17
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    no i meant what i said

    and it you read my other post , i did offer correct ladder help

    Quote Originally Posted by CFJunkie View Post
    mikeinco,

    I guess your 'precision reloading skills' and long term competitor mentality kept you from reading the sentence that followed that statement and recognizing that the OP never claimed to be a precision loader.

    The sentences that followed was:
    "
    If you get your reloading skills really tuned, you can get 5 to 7 fps SD and smaller extreme differences and that would include expected primer/powder ignition & burn variations shot to shot but you can't control everything.
    But the SD and max difference depends primarily on your reloading consistency."

    I am a bit disappointed that you, with all your knowledge of precision shooting espoused in your multiple posts on other threads, so easily assume that everyone has the same level of experience that you have or that they are equipped to follow or are even aware of the processes that you have apparently honed over the years.

    The OP asked for help in figuring out what his data means and the thread moved to variations in his approach.
    Maybe instead of consistently being a critic, you might offer some help on how the OP might improve to approach your "elite precision loading level".

  18. #18
    Administrator J.Baker's Avatar
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    Quote Originally Posted by mikeinco View Post
    no i meant what i said

    and it you read my other post , i did offer correct ladder help
    Why does everything have to be a fight with you? There's always more than one way to skin a cat.
    "Life' is tough. It's even tougher if you're stupid." ~ John Wayne
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urgent circumstances, desperate circumstances, profanity provides a relief denied even to prayer.” —Mark Twain

  19. #19
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    Quote Originally Posted by J.Baker View Post
    Why does everything have to be a fight with you? There's always more than one way to skin a cat.
    Not in places like " Townsend Montana."
    Remember that all knowledge in this country originated in the East and gradually spread West. lol
    Some obviously hasent arrived yet.

  20. #20
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    My, my, my....
    How the 'ol forum has changed.


    How ya doing Yobuck?
    Keeping out of trouble?
    We're no longer down there by you in south Brevard Co. A couple years ago we moved up here on the Fla / Ga state line in a little farm town called Jennings.
    Enjoying the open areas and plenty of woods.

    Do kinda miss the coast. Especially the beach. And maybe the scantily clad women on those beaches. And maybe... Ah, never mind.
    'Scuse me while I whip this out...!

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