Dude: I don’t know your name, but thank you so much for the information you’re putting out. I’ve been binge watching your videos while developing a load for my Win 270 130gn with 58 grains of H4831SC. 2940 fps I can now cover a five shot group at 100 yards with a dime consistently. I think most people get caught up on “chasing a rainbow” rather than defining their parameters for their intended use. I am now currently developing a load for my 7mm Rem Mag using 64 grains of the same powder and a 162 BT. 1/2 groups @100yrds with 2900 fps + velocities is food enough for me. Again thank your for the videos.👍
It's crazy how far you F-Class and benchrest guys take things... I would've never thought of any of this and it's not something that I would ever need to do but it's extremely interesting to me. Great video as always keepem coming brother!!!
The Math part is.....taking as many variables as possible and turning them into a known constant. This reduces stacked error, yielding statistically the most consistent result.
Hallaulla, someone that sees the big picture, this is why I like your channel, and point others to it, Keep up the great educational vids for everyone, good one Keith,
Thank you once again, great stuff, I’m starting to get an understanding of all that goes into precision. Thank you, the shortest part of all this is your videos everything else takes time.
I'm glad I stumbled onto your channel, learning alot from you. The no-go zone, for example, now makes perfect sense the way you explain it. Even though i noticed actual cartridge chambering marks showed variances, and subsequent velocity tests hinted at the problem, I had not relaized till you said it that variances in jump distances and cartridge runout make make a larger percentage of difference when that close to the lands vs being further from the lands. Its all about the percentages. Thanks for that nugget!
Ah the conundrum of hand loading. You spend some money, do some testing, conclude you need to improve a facet of your process which often requires more precise measurements, better data acquisition and the purchase of more accurate tools and improved methods of testing and then you start again. I am really enjoying your content. The only regret is not finding your channel earlier. Clearly your process is iterative and has proven results and I look forward to you sharing more of your wealth of knowledge to fellow hand loaders the world over. Cheers mate.
Love your content Keith! With out going down the rabbit hole of trying to reduce the ES/SD what would be considered reasonable figures of ES/SD? thanks for all the great info.
Very good video. I would only add that if, when you shoot your two sets of variable extreme examples, you keep every other variable as close to zero as possible, you will maximize the difference your two extremes will make because minimizing other variables tends to minimize your initial ES².
Your closing statement is probably the only part that allows anyone to maintain sanity. I think many invest in ES to a fault. This explains that more is going on than the bare number which I have believed all along but never fully understood. Many great groups have had crazy ES.
Thank you Keith, any pointers to which 3 areas bare no fruit and which 3 areas would be worth spending time on? (Or is that cheating? 🤔) great content. 👍
I like your videos as they confirm the things I believe to be true or a factor in the reloading and precision shooting world today. Next please don't get mad or insulted, as I'm old enough to remember the Dennis the Menace show and you could pass as his Father or his father's brother. I only bring this up because if he was telling us what you're saying the show would probably still be on the air. And as silly as it was it's still better than a lot of garbage broadcast in these times.
What's the red dot mount on the left chronograph? I've heard they're necessary in some applications because of the rather narrow cone the radar can see.
Then include the error of the chronograph itself for yet another variable. I totally get what you're saying here, but I like what you said in one (or more) of your previous videos... it's the groups that matter.
Master, trying to learn here, I have seen a SD of 8 and ES of 18 with 1" groups. Also have seen SD 13 and ES of 27 with 1/2" groups so, it's correct to go with what your target tells you and not get stuck with SD's and ES's ? TIA
I am only building a load for 600 yards in 6.5 Creedmoor. Velocity goal is 2700fps using 140grain bullets. I have found a load between 40.0 and 40.1 grains of H4350 with average velocity of 2712 and 2722 respectively. Both shot extremely well. My question is is it worth it to try and load some rounds between these i.e 40.05 grains? POI for the loads were almost identical.
@@sasquatchrosefarts there is a big difference in ideal aerodynamic profile for something moving slower than the speed of sound vs faster. Its pretty obvious when you look at which airplanes are 'pointy' and which ones are more round nosed or teardrop shaped. I'm no aerodynamic engineer so won't delve too far into the reasons why other than to say I believe it is about stacking shock waves and stability for supersonic flight, and frontal surface area in contact with the air and reducing the low pressure pull/ turbulence on the tail for subsonic objects.
I'm interested in your results and experience (as in how much testing & RD you've done on 6.5 CM). I ask this because I got a RPR in 6.5 last year to shoot F Class Mid and LR. I know it's not an "ideal" rifle for this but, F Class is more a fun/hobby/learning endeavor for me right now. I shoot SR, IDPA and USPSA on a more competitive level. I'm also running 140gr Hornady VLD Match and Nosler RDF. I'm using StaBALL currently at 42.9gr and it's giving me 2685 out of a 24" barrel, last SD/ES was 2.45 & 7 respectively & .008 off lands. The research I've done on others testing, seems to indicate that I will do best at around 2725-2790 but, I haven't done much load development yet. I am, however running best 100yd groups at 0.233 (less than 1/4 MOA) and worst at 0.42 and those larger groups were due to horizontal spread which were probably more the wind or me. This is also having removed the Muzzle Brake and running a tuner.
No go zone interesting. I used to start at 3 thou jump. like the concept of tolerances and significance of primer weight. A scale of limited returns. I'd love to see this talk given to a punter at a bar .. G'day...my name's Keith ..whatdya reckon bout this...🤣 I'm still recovering from no velocity flat spot node.... thanks again..
@@winninginthewind 308Win ja all in the X area. Ofcourse there is many variables affecting but in theory if we just consider powder presicion in reloading process. Thank you.
SD and ES: apples to oranges. We need stop treating & talking about group SDs and ESs as if they were independently manageable characteristics of a load’s performance. SD is an intrinsic distributional parameter (or calculable from intrinsic parameters); the sample SD is an estimate of the true, underlying SD. You can manipulate SDs by tinkering with all your reloading variables. ES, by definition, is a sample-based statistic and hence a random variable with its own probability distribution. You may not compare, contrast sample ESs outside a statistical framework; the notion of a single, representative ES makes no sense. Properly, you’d have to say something along this line: for 20-shot strings, there is a 95% probability that my sample ES will be 10 fps or smaller. You cannot manipulate the sample ES distribution directly: tinker with your reloading variables, which affects your load SD which in turn affects the distribution of sample ES. From the study of order statistics, we know how to calculate the expected value and distribution of the sample ES for any known distribution. For a normal distribution, the mean ES and any ES percentile are proportional to the underlying true SD, the proportionality constants depending on sample size. Determining the proportionality constants (available in the literature) is tedious requiring numerical integration or computer simulation. For example, for normally distributed data and n = 5 shots, mean(ES) = 2.33 x (true) SD 90% ES UCL = 3.48 x (true) SD and for n = 10 shots mean(ES) = 3.08 x (true) SD 90% ES UCL = 4.14 x (true) SD As group sizes increase, so too do the sample mean ES and sample UCL ES as we’re more likely to see extreme values in larger samples. In reality, we really need to compare load group SDs. There are tests for significant differences between variances but they are problematic for small samples. Using the sample SD in place of the true, but unknown population SD fails to acknowledge the inherent uncertainty related to sample size limitations. It might be more prudent to use an easily calculated upper confidence bound of the SD, especially when n is small. If the data are normal, we know how to do that. One conceivable, back door use of the ES would be to ask how small a (true) SD would I need to be to be assured of not exceeding a target ES with a specified level of confidence. For example, if you wanted to be 95% confident that your ES would not exceed 20 fps in a 25-shot string, the (true) SD would need to be approximately 20 fps/5.17 = 3.87 fps. A second use might be to eliminate unacceptable loads. You might chose to reject a load for further testing if you saw a 50 fps ES since, for your purpose, 50 fps would never be never acceptable.
