03-13-2020, 11:16 AM
Bobke Wrote:Seems like your better node is in between 28.1 and 28.5gr. 28.3 might be a place to play. POI is more consistent in that range. What are you doing to determine optimum loaded COAL or distance to lands? How long are you running these, or did I miss the detail? In my experience, Scenars are pretty jump tolerant. Might be worth further investigation trying multiple .003-.005 variations of loaded OAL in the 28.3 node from your current starting point.
Also, if youve got 10x firings on these cases and they havent been annealed, you may have some real variation of neck tension which might impact your results, as well. Primer pockets still tight?
If needed, I might test a little more around the 28.1 to 28.5gr.
The next test with the two loads 28.4gr and 29.0gr will give more info on witch one of the nodes to focus on.
I edited my first post with info regarding jump for this bullet and load. I currently have 1.0mm (~0.0393") of jump to the lands.
I have a modified case and the Hornady COAL measuring rod that gives me the MAX COAL, all measured on the ogive (BTO), not the tip (COAL).
Regarding jump with the Scenar, I have another experience. And with the exact same bullet, 108gr Scenar. In my other Grendel barrel I shot these bullets with 0.2mm (~0.007") jump to the lands. And that shoot very well.
With this extended throat on the current Krieger, that would not work so great since the bullet is not seated enough if 0.2mm jump would be used. With the 1mm jump that I have now, I think that the bullet is seated 4mm in the neck of the case. So I did not wanted to go any closer to the lands as a starting point.
If I need to, I will of course test different seating depth for more tuning.
The cases have not been annealed, and for sure I have felt difference in the neck tension. Felt a little loose primer pocket on one of the cases when seating the primers, but it was still seating tight, but a little lighter than the others.
The cases might be one of the week links in this. The last cases was loaded yesterday for this second test. It might be the last run with them and I can take the newer ones for future tests and shooting. Have 100pcs that only have been fired a few times.