Ladder testing

Discussion in 'Long Range Hunting & Shooting' started by Clem Bronkoski, Aug 12, 2019.


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  1. Clem Bronkoski

    Clem Bronkoski Well-Known Member

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    I've heard about this but never actually understood it. i always worked up loads until my rifle shot a good group. But after reading a couple threads on it I started watching videos about it. And it makes a lot of sense. My previous shooting was always no more than 200 yards. Not far enough to really tell if I was getting optimum performance from my rifle/load.
    Now I am going to do this with 2 rifles. My model 70 in 270WSM and my soon to have Begara B-14 in 6.5CM.
    I plan on doing the 10 shot method in .2 or .3 gr increments and do it twice to verify my results. Hopefully I will get a plateau up around the top end velocities. Once that is done and find the sweet spot I'll start playing with seating depth to get the most out of my rifle.
    I will take any advice on this.
     
    Rex Tharp likes this.
  2. Dog Rocket

    Dog Rocket Well-Known Member

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    For the Audette ladder to work reliably you have to have an extremely accurate rifle and an extremely stable and repeatable shooting position. The shooter as well needs to be as good as the equipment. There are a myriad of way to mess it up. That is why I don't recommend it too often.

    OCW is more reliable for the vast majority of shooters in my opinion. Although with OCW, the temptation is to look at group size. Some people can't seem to look past that. They just don't get it. The temptation to ignore the method is strong.

    I have done both many times. My personal process has gotten extremely abbreviated. I no longer care about the absolute best group. Chances are, it won't be that small on another day anyway. I accept a lower level of precision on a particular day for a greater level of consistency over time.

    I'll work up to the point I see pressure indicators using chronograph, micrometer, looking for ejector marks, the appearance and location of the powder ring on the neck, all taken into consideration to give a comprehensive picture. 2 rounds per charge. 0.2 grains apart.

    It has been my experience that the most tunable and consistent loads show up somewhere in the area of 98% of max for my combo. (This should also be a mild enough load to keep you out of trouble if you are shooting in the summer time). So, I load 10 rounds each of -0.2gr... 98%... +0.2gr... +0.4gr.

    I shoot them at 200 yds and see which group strikes the highest on the target. I want the barrel to be on the upswing in it's cycle, rather than the down swing. (google positive compensation). I shoot at 200 yds because that is far enough for any factors that might live inside the noise at 100 to show up and make themselves known, but is still close enough to control or account for environmental conditions.

    I then begin seating depth trials in .005" increments.

    Lots of people would disagree with what I just wrote. I'm sure they will show up shortly....
     
  3. ShtrRdy

    ShtrRdy Well-Known Member

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    I've been calling, what the OP is describing, as the Satterlee method. I don't know if there is a better name for the method but "ladder" is not it.

    The Ladder test involves load a single round for different charge weight. The charge weight is spaced 0.2 gr or 0.3 gr steps. Then you go fire them at distance - e.g. at 400 yards. After firing the cartridges you look to see where sequential shots ended up close to each other, and with small vertical difference.
     
  4. Clem Bronkoski

    Clem Bronkoski Well-Known Member

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    Rocket - Like I said before, this is all new to me. I always loaded different charges and looked for the tightest group. After reading your post I started reading about the OCW test method. That sounds like a pretty sound method of working up a load. The article I read on it the author loaded up 3 rounds each of 5 different charges. But instead of shooting three shots at one target then 3 at another target he had set 5 targets up and fired the rounds in a "round robin" type shooting one shot of each charge at at different target then repeating this 3 times allowing the barrel to cool between each shot. This eliminated the factor of heat build up or fouling in the bore.
    I believe I MAY just do this instead of the ladder test. Or maybe do this after the ladder test. Its not that I doubt my or my equipment's ability. This just sounds like a better test initially.
     
  5. Dog Rocket

    Dog Rocket Well-Known Member

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    You are correct, I missed this part...
    I spoke with Mr. Satterlee about his method last year. He had the opinion that the thing most get wrong with his method is that they don't put the work in on brass prep.

    The other aspect most fail to realize, is that he uses heavy for caliber bullets, slow powders, and loads that are at the max+ end of the pressure curve.

    Attempting his method any other way isn't likely to result in repeatable success.
     
  6. Dog Rocket

    Dog Rocket Well-Known Member

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    The "round robin" aspect is the only part of the OCW, that I am at odds with. It is my observation that over the course of so few rounds, the effect of fouling is inconsequential. The effect of breaking your solid shooting position after every shot is immediate.

    Therefore I allow proper cooling between groups, but shoot all rounds within a group from a single solid position.
     
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  7. YZ-80

    YZ-80 Well-Known Member

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    I’ve done both methods but found the basic charge ladder to be the most effective use of my time. I guess I’m not shooting far enough to necessitate some of the more elaborate methods. I load escalating charges at each rung of the ladder and just shoot for group size (sometimes 3, sometime 5 shots each) I add a bit more rigor to my method by keeping my ES under 20 FPS and requiring less than .5 MOA vertical dispersion at 300 yards. This has got me comfortably dispatching whitetail out to 400 with my 6.5 Norma and my 6.5 x 47.
     
  8. Clem Bronkoski

    Clem Bronkoski Well-Known Member

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    From what I understand in the short research I've done that both the ladder and the OCW methods have their merit. But I do believe now that the OCW is the better method. With it you should be able to determine what the best charge weight for a given powder is and then play with COAL (seating depth) to fine tune that load.
     
  9. 8andbait

    8andbait Well-Known Member

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    I like doing a ladder style test when I get a new cartridge I’m not familiar with or using new bullet or powder.

    Usually ten shots incrementally climbing in charge weight will tell me where pressure is and usually a good area to focus on.

    After that I do an OCW in the powder range I found and this usually reveals the “node”.

    Shoot a few over the chrono then confirm it with drops at distance.
     
  10. 8andbait

    8andbait Well-Known Member

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    I prefer to do round robin with three minutes between shots. I feel it spreads fouling, barrel temp and atmospheric conditions over the course of the entire test.

    It seems like my loads are more consistent with that method and it satisfies my OCD.

    But I say what works for you is the best way to do it.
     
  11. fightthenoise

    fightthenoise Member

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    I've started doing a ladder at 300 to determine powder charge and then doing an OCW-style round robin group shooting session to determine proper seating depth with the charge weight I arrived at in the ladder. I follow the Berger article for testing seating depth. Due to the way these threads usually go, it's pretty apparent that there are several good ways to skin this cat.
     
  12. TheLongRanger83702

    TheLongRanger83702 Well-Known Member

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    I found this very helpful
     
  13. Braunschweiger

    Braunschweiger Well-Known Member

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    I find that your reloading practices must be very sound in order to do Satterlee's method. Everything has to be consistent (neck tension, case capacity, charge weights, trim length, etc)

    I used to do OCW but now I do Satterlee method so that I'm limiting component usage as well as maximizing barrel life. I've confirmed it works as "advertised" as most of the nodes I've found, doesnt matter what powder I'm using, it will still shoot well and velocity SD and ES are very low.
     
  14. vancewalker007

    vancewalker007 Well-Known Member

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    It's worth shooting singles with increasing powder weights and measuring velocity to discover the charge jump points your rifle will create. Loading groups on those velocity jump points basically wastes time and components. This method also allows you to safetly discover your rifles real max. If you try it you'll be surprised at the speed jumps you'll see over 0.2 grains even.