Thanks, I'm out now, I have my own method, with my own terminology, lol
I also think you are steering guys toward a flat spot in velocity zone. I myself, never have shot H4350, and have never really seen a flat spot with any powders I've used, other than the plateau before pressure. H 4350 known for flat spots. And like you, I do chrono every shot start to finish of load dev.
I myself have never shot a True ladder test, one aimpoint, multiple shots, I'd use project board with this style template, work left to right, low to high charge. That way I do not have to keep track of individual shots. Just eyeballing the hits tells you which charges hold identical vertical. chrono keeps things in perspective.
OK, well Im going to bust myself early, even though I said I wouldnt, since Milo thinks Im asking leading questions towards the flat spot but my prior load was 39.4gr summer, 39.5 winter via ocw at 100 yards, averaging ~2980 +/- 10 fps.
I was originally going to try and demonstrate that the flat spot was a fluke but Ill be damned if the saterlee part of this test didnt support my load. So thats the numbers. Wasnt trying to lean towards the saterlee method, just the opposite actually but I cant deny what Ive laid out here (small sample sizes aside).
Now... the target shows exactly the opposite, 39.4 had the largest vertical of any of the tests with the test loads directly above and below it rising to the higher and lower side of it instead of clumping aroudn themiddle, not at all what I was expecting/hoping. I was expecting the target to support the prior load and the numbers to be way off, so my paradigm has been shifted.
So if it seems Im leaning one way or another, its really just me squirming in the middle LOL
I like that target with them spread out on the football stitches, I have done something similar for OCW when I have a new rifle that needs to be zeroed still and I have no idea where its hitting or how well it will group. Ill shoot it in the middle of the big board so its there to catch the shot whereever and then Ill adjust my sights and then start my ocw on the same row without having to go down range at all to swap targets out and so on.
I'd ignore the velocities and look at the target IMO. Velocities are there to give insight into the target, not the other way around.
If you were throwing charges with low degree of powder accuracy the range of 37.9-38.5 is a pretty fat area where the elevation POI on target is pretty consistent, as is the speed. Vertical is not great for any one charge weight though (looking at just two bullet impacts).
I don't like the range around 38.8 to 39.4. Across those three charge weights the vertical moves pretty rapidly up the target.
The charge at 40.0 has some of the least vertical, and also overlaps 39.7 (which itself has not much vertical). The velocity ladder also confirms a bit of a flat spot there. Don't know what's happening above those charge weights.
I personally would do another confirming ladder between 39.5 to 40.5 grains in as favorable conditions as possible. I think right around 40 grains has a lot of promise. Not sure what I think about the SD/ES of those loads, but I'd be curious what the target says if you shot again. Who cares what the velocity variation is if the target shows the least amount of vertical?
Side note, 3050 ish with a 105 is a pretty common load for 6XC. If you wanted to shoot at 2960-70 then just shoot a Dasher.
Thats what I was intending to set out to do, to show that the chrono was fools gold and the target was what mattered most liked I described in response to Milo. But this particular target flies in the face of what I had tested before and the chrono backed up my prior hypothesis.
So the opposite of what I was expecting!
What I find interesting is that you and clcustom1911 suggest looking into 37.9-38.5, the others all say to look at the area of 39.1-39.4 which is where you say you would avoid. And going off this one particular targets its the area that I would be inclined to avoid as well.
And I dont see how people are running 3050 with H4350, thats scary fast but Ive heard people reference it as well.
With RL16 I was getting accuracy at 39.8 gr for 3070 but 40gr with that powder was putting ejector imprints on the cases in not super extreme temps. Extreme temps in texas get hot and only being .2 away from pressure in the enjoyable 85 degree weather with a powder that gave me the only bad carbon ring Ive had was enough to push me back to H4350.
Ive got a dasher barrel on the way, just waiting for it to arrive in the next month or two
38.8 grains happens to be "3% less/ or 1.2 grains less" than 40 grains, which Newberry suggests is where the next node down is from 40, and I'd count those two charge weights as having the least vertical, as well as being nodes by looking at the vertical dispersion.
Even though 39.1 to 39.4 have lower ES they appear to be in the scatter node. Well that's why I gave up using a chrono during a ladder test. I just look at the vertical on paper.
Since you are doing .3 grain increments and the tightest node could be in between somewhere, I'd shoot 3 shot groups at 500Y of .1 grain increments, low from 38.6-38.8 and high from 39.8-40. Actually if the pressure isn't hot at 40 I'd personally choose this high node area and concentrate on it from a load density and a higher velocity perspective. Come hot temps if there is a pressure problem you know where the low node is. Or reduce the high node charge a tenth or two to duplicate the velocity you come up with.
I'd still like to see how an OCW at 100Y correlates.
That's good you already had the seating depth down from previous load work, your rifle shoots pretty good, especially considering the bullet you use!
Some of my above comments for reasoning apply here as well about the numbers vs the paper. The limit of 40 is kind of a soft cap, its a bit tight on extraction but nothing that a good oopmh cant take care of, that said 40.5 is leaving ejector imprints and is clearly over the top and that was found on a day in november when it was 70-85 as well. In summer when its 100 that 40gr gets an appreciable bit tighter which is why Ive never really ventured that far up too in depth.
So we now sit at
steelhead- seating depth test at 39.2
clcustom1911- ocw 38-39
rackops- ocw from 39-40
ranger188- ocw from 39-40
svtuh- seating depth at 39.3
isofahunter- seating depth at 39.1 @ 500
skookum- seating depth at 39.2
sheldon- another higher ladder for confirmation of the top end
steve- 38.6-38.8 and 39.8-40 samples @ 500, 100 yards ocw to corroborate.
Thats 4 for seating depth, 4 for ocw, 1 ladder.
Brass was all processed yesterday. Im going to try and maintain some will power and keep holding off on powdering them up just yet to see if the crowd swings more one way than the other.
