Thanks for the suggestions, and for taking the time to reply.
I'm with you, I really thought it was some kind of Garbage-in,garbage-out problem, and as you said, normally, one would be happy just to have a functioning, real-world drop chart... but I want to know WHY, dammit.
Yep, this is a perfect example of why there's NO SUBSTITUTE for shooting your Rifle/load/scope combo EVERY HUNDRED YARDS,(or 50 if you can)- and logging the dope in your data book. Change any one of those three elements, and you need to chuck your data book, and start a new one.
I'm using 1:10 twist, pretty standard.
I have checked the scope reticle against a long ruler @ 100yds, measured with a 100-foot tape, not a LRF, although the LRF did agree with the tape. The MOA reticle subtends exactly 1-inch per hundred yards. I also held the rifle steady on a bipod and rear bag, while my son cranked in elevation, 4 clicks at a time, it tracks right with the ruler, all the way to 45 inches/SMOA, which is all the usable adjustment I have past my 100-yd zero. Repeated several times to be sure, going up, coming down, etc. I feel confident about the adjustments.
I am pretty confident about my weather data, I use a Kestrel
4000, which outputs directly to density altitude, if you want it to, saving the computations... I have checked it against 2 other Kestrels, and against the weather station at the school 1/2 mi down the road, via the "Weatherbug" program (pretty handy), and it's good. A thousand-foot change in density altitude only changes the impact about .5 MOA at 1000 yds, not nearly enough of a factor to explain the discrepancy here.
You're right, it almost has to be my chrony data. I have, of course, had wild readings, especially in "weird" light, but usually just 1 shot here and there, so high or low, I knew it was an error, and discounted it. Never got the feeling it was "consistently" reading high (or low)... but what else could it be......?
I think you are correct,that I am dealing with a couple of factors that stack up in the same direction- that the (advertised) BC is a bit optomistic, and my chrony readings are a bit optomistic as well.....
I have been shooting the Bergers, because they shoot so much flatter (25.75 SMOA @ 1000), buck the wind so well (6.0 SMOA @ 1000, with a 10mph full-value wind), and lately, I have been shooting more matches, than I have been hunting. The most fun are the unknown distance matches, no LRF's, no sighters, first shot is for score.... and those slick Bergers are a great mistake eraser, because errors in range estimation, or wind estimation, are lessened. "Shoot right through it", as they say...
But those Ballistic Tips just KILL STUFF DEAD, and I like using them for hunting, but I just haven't had the confidence with them, because I couldn't resolve the dicrepancies we have been discussing.
Thanks again for your time, you're helping me get to the bottom of it, always helps to get a fresh take on it. I'm going to try another chrony side-by side with mine, if I can, and with more than one gun.
Sorry if we've hijacked the thread, the discussion seems somewhat relevant to the bullets that were asked about.
Stay safe, and good shooting!