Re: Need help deciphering OCW test results
Basically what I reported to Dan was that, I have several rifles which will duplicate exactly what your target shows. While this is definately not representitive of the vast majority of loads and the rifles which shoot them, it does happen.
As Dan mentions, when doing this sort of testing, you will generally see, some grouping which will gradually trend smaller towards the nodes or sweet spots. My point above was that, sometimes however, you see such results as 1.5" groups dropping into .5 groups as well. Normally your groups will go from 1.5" to 1", then so on and so on. Does this mean that you should abandon the use of a load similar to what you have in group #2, not necessarily, as it might be fine. However, it does warrant more testing, as I mentioned.
The rifles I have, which exibit the similar tendencies of your groups, will shoot several loads constantly into 1" to 1.5". However they will drop under .5 with only one load combination of bullet and powder. These particular loads, for these particular rifles, have been repeatable through the years, in varied conditions and through different lots of components. With the changing of component lots, the load might vary a couple of tenths one side or the other of the original powder charge, but get past this particular area, and the groups spreads out drastically.
I agree with what Dan say's on this type of testing. It is always best to have a combination which has a more visable or defined sweet area. This in most cases allows for subtle changes to occure and still maintain the intergity of the load and any ballistic data one might have developed for it. However it can be, as I mention, repeatable within a narrow range as well.
There is merit, from what I have seen through the years, for both the OCW and the Ladder test. In fact I generally incorporate both into my load development. I guess you could call it a hybred. I generally set up a half dozen pasters on a target, and set up my seating dies to be somewhere right at the MAX OAL to allow the rounds to fit the magazine. I then go about shooting somewhere from 3-5 shots at each dot over the chrono and work my way up, with a particular powder. I generally try to get 80%+ densities on my loads so this helps to narrow the choices some. Once I hit an area which somewhat has the velocity I am looking for, and shows some promise, I will drop back to working on the seating depth.
Sometimes it all comes together, sometimes it's a bust. However, when I am done, the end result is generally as good as it gets, with that particular load or rifle. I do have to mention that I have only worked with basically straight factory rifles for the most part and only a couple of customs through the years. However, my process has been the same for all. I look for the best groups, at the velocity level I am trying to reach for a particular load, and the lowest ES and SD. Sometimes however, you don't always get what you want, but thats what keeps it fun.
You on the right track, and based on your other target, obviously both the rifle as well as you, are definately capable of determining the end result.
Mike / Tx
"Heck why would I lie, most folks don't believe the truth when I tell them"