Interesting. I listened to the same podcast from Hornady and while I don’t think they are incorrect, I think they are missing the point of other tests; most are not trying to develop loads that produce the smallest groups, they are trying to find a load with the smallest deviations with any change in the process. In a similar vein, I offer the writer of the article is misinterpreting the results of the Optimal Charge Weight maps. He seems to think the OCW is the group where the difference between the impacts and the median are minimized. Almost. The OCW is where the difference of the median of the impacts across a spectrum of charges is minimized. His interpretation of the OCW amounts to finding the load with the smallest group. Again, this misses the purpose for the OCW load development. Rather than looking for the smallest group, he should look for where the center of each group prints vertically. The OCW is the load where this point is relatively the same, vertically, regardless of charge. Thus, for whatever reason, any change in velocity won’t change the impact as much. This provides a very forgiving velocity to use with ballistic software and more predictable data.Originally Posted by ccmdfd
Quickly looking at the .223 data this way, I would call the OCW closer to 22.9. Which matches closer to his velocity node recorded at 23.1.
Humble apologies if I am wasting your time with this discussion. Just something I'm seeing over and again.
https://www.youtube.com/watch?v=oTWD...RldmVsb3BtZW50
Explained way better by the developer, Dan Newberry himself.
Oh, not wasting my time at all! Please don't feel like you're doing that.
I appreciate any and all discussions on this topic. And glad that you are able to look at his methodology and realize the issues. Watching many different YouTube videos on this it seems like people are all over the map and the definitions of what exactly the ocw is vary significantly, at least the technique of it.
Keep on posting!
Man, this is 1000% true. Every expert says something different. I didn’t really have clarity on OCW until I heard Dan explain it himself. I developed a load for a .308 four or five years ago and he had a service where you could email him pictures and he would walk you through the process to find a load. Otherwise, I wouldn’t feel as confident that I know the “right” way.
There are so many things that affect ammunition. I have found that the thing which affects accuracy the most is a quality barrel, a quality bullet, and neck tension play the the biggest part. Powder OCW won't turn a 2" group into a 1/2" group, but it can make some improvements.
I am not a statistician or an engineer, but I am around them pretty frequently. The thing that I keep hearing is that you really need a lot of samples to get an accurate conclusion. @Molon likes to use 10 shot groups to do his testing and I find validity in this. I usually shoot a 5 shot group and if it shows promise, will repeat the group on another day just to be sure. I will also shoot the load at longer distances, say 300 yards, as it is easier to see the dispersion.
-Seconds Count. Misses Don't-
I get conflicted with how many shot to fire for a given test. In the past, I've been a great proponent of 10 shoot groups. With today's shortage of components and increased cost of same when available, it "hurts" to shoot a bunch of 10 shot groups. Forget 30 shot groups. But I don't disagree with the premise. More shots, more data.
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