What sucks about all this is my 6.5x284 doesn't group worth a darn at 100 yds. Then again, many have told me 6.5x284s typically won't group well at 100 yds. I am thinking 300 yds would be a good distance, because it would give me a better picture of how the rifle is "moa-ing" without introducing all the environmental variables that can mask a good load at longer ranges. For now, load development at 100 yds will have to do.
I have shot two matches now. After the first match I wound up building a Light Gun class rifle. Right before the match I managed to shoot four consecutive groups in the .4 range at 100 yds, with the best being .174. They were two different loads, the first two group's rounds having been sized with a .293 bushing and the last two with a .293. I selected the better of the loads and shot my match--not that there really was much difference.
I didn't shoot great at my second match (last month); my groups were 8.75, 10.563, 9.125 giving me an agg of 9.479. However, no one else was shooting great that day, and I wound up tied for first in score and third in agg. The top two aggs were 7.667 and 9.375, but both of those were shot in the second relay where conditions became very favorable. I had top agg of my relay (first relay).
So I don't know what kind of groups good 1000 yd loads should produce at 100 yds in a 6.4x284. I think my 6.5x284 should produce .3s at 100 yds, but I am not there yet. I tried some slightly different loads today but found no real improvement.
My dilemma is do I take the best ES or the best group, because they do not--nor have I ever seen them--come from the same load. Part of this dilemma is my own fault--I should have shot two groups from last match's load vs one with good brass. I shot one load with brass I had set aside--I don't remember why I set it aside, all I was able to measure was a difference in case length--and it shot like crap. The next group from this load was .36 with an ES of 19 (all dispersion horizontal), but I wish I had backed it up. Then again, when I add that group to the other groups I have shot with this load, I get three groups in the .3s, but ES's are 37, 24, 19.
Today, one-half grain more powder gave me .56 with an ES of 12 and .5 with an ES of 19. The dispersion in these groups were mostly horizontal. Then again a half grain powder increase probably isn't a significant difference in a 6.5x284. I did gain about 30 fps. The last load was a full grain over my match load, it didn't shoot well at all.
I'd really like a string on .3s with ES of 10, but that may take some time. I think I am going to bed about an inch in front of the recoil lug. I think I may be putting a lot of stress on my 700 long action with a fully floated LV barrel, Tubb recoil lug and all. I think I�ll also try my VLD chamfer�I think I can get neck tension a little better than I have now. I should give the .291 bushing another try, I should probably step on the powder charge some more, and maybe even mess with seating depth again�though every depth I have tried other than what I have now has opened the groups up. It takes time to progress through all they one change at a time, but then again, that�s why I�m in this game�right?
I think for the match next week I'll go with the same load as last match. My new FL bushing die gives better concentricity than the neck die and body die process I was using before and that will be a plus. I'll also use a bit heavier chamfer to tweak seating tension consistency, but I'm not going to change to the VLD chamfer until after the match.
