Pressure flats

Discussion in 'ELR, Ballistics & Bullets Board' started by tomswede, Jan 8, 2018.

  1. Berger.Fan222

    Berger.Fan222

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    Exactly. The only way you know for sure you have a load capable of shooting a 200/200 is to shoot 10 shots and put them all in the 10 ring at distance. Then you start trying to increase the X count. 200-10X to 200-15X to 200-20X. But you gotta shoot 20 shots to know for sure what the X count potential of that load really is.

    All the load work up techniques attempt to reduce the time and effort to get to that point. But in the hands of different reloaders, art gets mixed in with the science and all the details of brass prep and projectile sorting and so on suddenly matter, so my art might be different from your art.

    Even with 20+ shots of load work up, all I ever know is that a load has promise. Until 20 shots are on an F-Class (or another appropriate) target at distance, I still don't really know.
     
  2. retired

    retired

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    so the question is part of the problem.
    no discipline is referenced.
    a hunter can test with 3 shot groups.
    a short range br shooter with 3 and 5's
    20 rounds only apply to prone/position shooters..a narrow world
    long range 600/1000 shoot both 5 and 10 but not 20.
    elr is short strings from 2 -3... kof2m does 5
    soo generic questions seldom see a specific answer.
    i'll stick with ladders.

     
  3. Meangreen

    Meangreen

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    I don't mind shooting larger round counts to be statistically confident in what the load will actually do. I also don't follow Audette's method of starting 20 increments below maximum. There is a very narrow range of performance I am looking for. I couldn't care less if there is a big node 4 grains below max charge.

    I am looking for a high node within more like 1 or 2 grains of max. If these don't show significant promise, I move to something else.

    Shooting 10 shots or more at a single point of aim will show you what is going on harmonically with your barrel in the shape of the group, in addition to the velocity data you are gathering.

    I also shoot most groups these days at 200 yards. At this distance, you get enough separation to actually see any stringing very clearly, yet it is close enough that any environmental elements can either be controlled or easily accounted for.

    I'm gonna get hammered, but there it is.
     
    Last edited: Jan 11, 2018
  4. rhovee

    rhovee

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    I am new to the Forum and have found myself in the deep dark hole of reloading. I have been trying/reading different load development techniques that work. Ladder, OCW, 10 shot load development, and asked Alex tons of questions!. I shot my first ladder a few months ago over a chrono. It was happen stance that i ended up with .9 grain difference in powder charge that had 1/2" vertical at 350 yards over 3 shots with 5 FPS difference. However, when i took my next shot the speed was the same and the POI jumped 5" vertical. This tells me that you can't always just base loads of velocity. I went back and shot (3) shot groups in the node and it wasn't as wide as it seemed on the chrono. I ended up with .4 grain difference in my load. But there was a total of 1.2 grains that had an ES of 5. This is a hunting rifle.
     
  5. tomswede

    tomswede

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    Guess I was a bit vague. Question really was intended for longer ranges, 600 yards and up. My personal interest is prone mid and long range, so in match conditions 20 shot strings.
     
  6. retired

    retired

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    but LARGE targets ? mil is a 2 moa 10 ring.
    if palma i do not know sizes.
    but not benchrest with a 20 shot string.

    see how a little LACK of info skews things.

    all have a good day

     
  7. tomswede

    tomswede

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    Still need good performing loads and good methods to develop them. Since the “flats” don’t make sense to me I wanted to gain some knowledge on what people do and the results they were getting.
     
  8. fredo

    fredo Silver $$ Contributor

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    Some shooters prefer a more 'quick and dirty' type of ladder testing to find that 'high node' that Meangreen explained so well in his post #44 above. Others seem to enjoy the actual load development & testing to the point that they prolong it to the point of exhaustion. Different strokes...

    Soon I'll be venturing into somewhat uncharted waters when finding some working loads for my .220Redline wildcat. Being a wicked overbore killin rifle, my testing will be most definitely 'quick & dirty'. With preliminary QUICKLOAD data in hand, I'll run a few 8-10 shot ladders at 2-300yds with chrono rolling. Will look for that 'flat spot' on target while watching for a 'flat spot' on the chrono that may betray an impending pressure spike. Shouldn't take but 50 rds to have something safe and accurate enough to take to the field and prove out at distance. Rifles and components are built so well these days that it don't take much to find a fine shooting load...
     
  9. CharlieNC

    CharlieNC Silver $$ Contributor

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    That's very close to what I do as well, with the charge range being narrowed down based on OBT using Quick Load. I do like to shoot 2 per load to have more confidence, specifically that a single "flyer" if in a scatter node can be misleading as appearing to be in a node based on comparison to its neighbors.
     
  10. milanuk

    milanuk Team Savage Gold $$ Contributor

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    ^^^ this!
     
  11. dmoran

    dmoran Gold $$ Contributor

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    RL16  7022016.png

    Used up all 4' of the target board (and a little extra) on that one..... lol
    Typical amount of Velocity to POI curves that I see, in ladder testing.
    Donovan
     
    Last edited: Jan 12, 2018
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  12. tom

    tom Gold $$ Contributor

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    Single shots, at about .6-.9% intervals allow you to know two important things. Max working charge, rough area's of interest on the way to there. I myself run triple ladders at .3% intervals once I narrowed it down. In my experience those "wide" 1% windows are coming from shorter distance tuning. At 1k, even a hummer has about a .6% wide window, and most are .3%....For the utmost level of benchrest precision that is.

    Tom
     
  13. retired

    retired

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    what do you think of rl16 ?
    i have not had a chance to try out what i bought.
    comming from an rl15 shooter.

     
  14. dmoran

    dmoran Gold $$ Contributor

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    Switched to it from RL15 (using those same components) in both my LT & HV Guns.
    Was repeatedly getting a little less vertical with the RL16, and its more temperature stable.
    It does require a longer funnel, to drop the charges, for the 6Dasher cases.
    Higher load density so powder crush also comes into play when seating bullets.
    Was already on long throats (.160" FB), which helps for the extra fill.
    Also find it to be "pressure friendly".
    Donovan
     
    Last edited: Jan 12, 2018
  15. Alex Wheeler

    Alex Wheeler Gold $$ Contributor

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    Dang that dashers almost getting BRA-BRO velocities :D
     
  16. dmoran

    dmoran Gold $$ Contributor

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    @Alex Wheeler
    That barrel is +3" longer then BRA-BRO, would be part of the reason.
     
    Last edited: Jan 13, 2018
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  17. tom

    tom Gold $$ Contributor

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    BRA-BRO still has ya by a tad when I feed it those "fancy" powders.

    20171126_095740.jpg
     
  18. Alex Wheeler

    Alex Wheeler Gold $$ Contributor

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    Not bad for 33ish grains of powder?
     
  19. tom

    tom Gold $$ Contributor

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    Fresh Krieger, BRA "version 2.0";)


    300 yard, pressure seeking/ladder from this morning. Looks like +-31.8 is a place of interest. Nice FLAT"ish" spot!

    20180114_111922.jpg
     
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  20. milanuk

    milanuk Team Savage Gold $$ Contributor

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    Interesting... if going just by vertical displacement, I'd almost pick something else. But going by MV...
     

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