phorwath,
Thank you. You bring up some good points that I will comment on.
First of all, I will say again that the ladder tests do show validity and if done correctly, will show good nodes. The fact that very knowledgeable shooters such as BH and others use it shows it can work. As I said before, the scientific method I use and the ladder test you describe borrow traits from each other in places. I have just found that the scientific method reduces error in your results because it more or less eliminates or significantly reduces wind, mirage, and shooter error as factors. It also shows little anomalies that are often overlooked or invisible with ladder tests. I'll get to this in a minute.
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I've more or less concluded that a ladder test cluster that also coincides with several consecutive loads with similar velocity (little velocity gain per incremental powder charge increase) is a potentially good powder charge zone, worth further research.
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For the most part, this is true. However, sometimes with certain powders in certain calibers, incremental increases in velocity are common and have no bearing on a good load or node. I have seen it numerous times in big magnums with H1000 for instance. I would run up .5 increments and the speed would only go up 10 fps and sometimes it would even get slower with more powder. The ladder would show that any of these loads were a good spot but in reality, the standard deviation on a 3 shot group of that charge would be 35 or something! So just because the velo is similiar in different charges doesn't mean it will always yeild a good load.
And on the opposite side of that point, there are many times where the scientific method will show a sweet spot that is inbetween the incremental charge below and above by as much as 50 fps! In other words, this "X" charge jumped up the velocity 50 fps from the last load but it had an sd of 3 and produced great accuracy. So the ladder would show it out of a peak and not worth pursuing.
Also, when graphing the ladder test, it would not show the other anomalie I have seen many times I call group shape. It is widely known in benchrest that group shape can tell you a lot about your load. "Roundness" of a group can be tweaked by seating depth and vertical can mean too little powder charge. Left/right spread groups in a no wind condition can mean trigger pull issues and so forth. These are things that scientific method will show while doing load development and the ladder can only show after a load has been "found" and then repeated in normal multiple shot groups which eats up more barrel life. For instance, when I was working up a load for my 338 thunder last spring, I found H1000 to give small sd's and produce fair groups at 100 yards in the neighborhood of 5/8" to 7/8" but the groups were always very round shaped and on the same area of the target no matter what charge was used. IRM7828ssc produced the same sd's(standard deviations) but shot phenomenal sized groups usually in the 1/4" to 3/8" area. However, despite having smaller groups, the groups originated on different places on the target with each incremental increase of powder and the group shape was always "stacked" vertically in neat, small fenceposts.
Well, when both of these powders were checked at 1000 yards, the H1000 shot nice round groups around .75 moa and the IMR7828ssc shot vertical fenceposts in the area of 1.5 to 2 MOA! Remember, both these loads showed good standard deviation. Group shape is important and the ladder doesn't show this until after the development has been "done" and Scientific method shows it while doing the development.
So to say you are killing two birds with one bullet by using the ladder test is actually just taking two bullets to kill one bird in my opinion. The idea that anyone can say the ladder test saves you ammo is simply false. To do what you or BH said and chrono and retest and then chrono and retest any ladder proves that it takes just as much time to run a properly conducted ladder as it does a scientific method test and possibly even more.
Now I will freely admit that the scientific method requires a longer learning curve to "read" what is going on. And I further admit that it is harder to do because of this. In the whole spectrum of shooters out there, there is probably less than 10% that have enough experience and knowledge to be able to make heads or tails of the data the chrono and paper target is telling them. But I would say 90% of them could learn it if they tried it. The other 10% are the guys who think chronographs are for sissys! Just load them and shoot them right?!
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As you have posted more than once, low ES and SD is mandatory for truly long range shooting in order to minmize vertical spread.
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I fully believe this to be true. How can 5 bullets having speeds that vary as much as 50 fps all go into a small group at 1000 yards unless the wind "lucked" them into the group. My luck dictates that if I'm not paying attention to it, the wind will take my bullets OUT of the group!
Even some loads that shoot in the .1" range at 100 yards from my 6br or 6ppc have sd's around 20 or 30 and that group stays pretty small until some distance is applied and then you wouldn't be able to hit anything but a flag pole at long range. Some at the top, some at the middle, and some at the base!
But as I mentioned earlier with the IMR7828ssc in my .338, low sd's are necessary for good long range accuracy, but they also need to produce good shaped groups sometimes to really be accurate out there at distance.
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So if good accuracy and precision can also be attained by developing loads with a chronograph, we kill two birds with one... bullet?
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As I said earlier in another post, if you are going to run a ladder with a chrono for ease of obtaining more information about your ladder, why not use the chrono to run a scientific method and throw out the ladder. It seems like running two things at once would be harder than just doing one thing at a time. ANd that can't possibly save you ammo. It's kind of like buying a car so you can get rid of your horse and buggy but instead tying your horses behind your car for more luggage space. It makes more sense to me to run a ladder because a guy doesn't have a chrono than it does to have a chrono and still be running ladders. Just my opinion though!
