You are right, it did not make sense. I also gave advice to group at advancing distances to get a feel for the load, in my case, it was irrelevant to know where it fell apart, getting that good of grouping at 500 should suffice.Mathematically, the 1” at 500 becoming 14-15” at 1000 doesn’t make sense. I haven’t experienced this. I do ladders at 500 then seating depth at 300 or 500. Maybe that helps. I’ll play with this more with the chrono this week. Have some finalized loads at 300 and 500 that I’ll take out to 1200. Thanks for taking the time to explain, guys.
This past summer, I had a 6x47 Lapua chambered after a 2 yr absence from shooting one. A mix up between the smith and I resulted in him throating it for dtacs, I was not happy. First it took close to 200 rds for the barrel to quit speeding up, but I was close with a load, or so I thought. So one morning I load around 20 test loads to be shot at 500, can't recall the split number wise, but did have 9 charges of the one that had been doing the best and was producing the best numbers, win win. Did not go as planned, as it seemed my seat depth was not good, what I did end up with from this charge was those 9 rds producing a vertical spread at 500 of maybe half an inch.
Ok, this should be simple, I run back to town, load 40 rds of same charge, seated long, throw the coax in portable mount, take die and caliper-comparator to find the seat depth.
This is where the rodeo started, testing at 100 yards, at .006" off the lands, shooting project board with 1/4" dots made with a sharpie, it matches up good with a Kahles dot. Making minute adjustments, the seat depth changes literally clocked themselves around my dots as I tested, I think my first set was just high right of the dot, and subsequent groupings just rounded the dots, and nothing improved as far as group size. Figure that one out.
Thank God on the way home I realized another amateur smith was just getting off work, I stopped by and had him spin the barrel off, I was done with it, it did get a 2nd chance at life as a Dasher barrel for a friend, working well this go with 110 sierra's. And I got a new Krieger to replace it, happy happy