Reconciling Ballistic tables with range results

[tarngmyna]

I have been working up loads for my .308, and have entered all the required data into several ballistic calculators, including BC and velocity. I have made several trips to the range and fire groups at the distances of 100, 200, 300, 400, 500, 900 and 1000 yards. The trouble I am having is that none of the calculators match what I am seeing from my range results. I have tweaked the velocity, thinking my chronographic might be off, but there is still https://xender.vip/ a discrepancy of 0 .3 or so millrads at the shorted distances, and up to a full millrad at 1000 yards. If I mess with the calculator settings to get the 1000 yard distance to align, then the closer distances are off. Is this common or am I missing something?

 

[Aftermath]

Lots of info here

Search function can save you LOTS of time and such

 

[Dead Eye Dick]

Lots of info here

Search function can save you LOTS of time and such

Thank you. I was just into the search and this was the first place on SH I found. My data, worked closely with Weaponized math. Went to the range with a new load, got my range data worked out to 1050 yards got and the loads MV. Fed all that into the Kestral and it was not even close. So for the last match of the year, I depended on my personal range data and conditions at the match were similar to the range session. So, had a good day, for me, at the match. Now I can get the Kestral squared away.