Handy tables and charts.

[Harry's Lad]

Is it possible that by attempting to belittle someone else's work, Dave, that you feel you're in some way trying to bolster Chairgun as the prime source of ballistic data for airguns? I'm afraid that's how it's looking, to me, anyway.

I’m not trying (or have tried) to belittle anyone or anything – simply pointing out that an error exists. I sited FillCalc (not ChairGun) as a source of comparison (although the same FillCalc algorithm does exist ChairGun2/3). You were the first to mention ChairGun in your post #24. I’m left wondering why you would accuse me of ‘in some way trying to bolster Chairgun as the prime source of ballistic data for airguns’ when it was you who introduced the topic in the first place . . .

Chairgun isn't particularly accurate either. Sorry to drop that on you, but Chairgun 1.8 said that I will need 68 clicks on my big nikko if I shoot AA fields at 55 yards, zeroed as I am at 23 yards wilth all other parameters as built.
Chairgun 2.? says - for EXACTLY the same physical parameters - I need 58 clicks. Practice tells me I need 56 clicks.

As mentioned above (my answer in #25 to Rich’s specific reference in #24) ChairGun has evolved, and continues to evolve, subject to specific and changing criteria. ChairGun1 had problems (and errors) in certain areas (although these were resolved by the last – V1.99 – iteration). Changing requirements lead to the adoption of a better mathematical model that had benefits in all areas and ChairGun2 was born.
Two clicks at 55 Yards is something around ¼ MoA; pretty good when ChairGun2’s specified accuracy is +/- ½ MoA. Did you actually measure the BC or assume a nominal value?

At the end of the day, does it really matter about a few clicks or a few fills? No, it doesn't.

Quite true. However, does 1/8” Inch of error in 55 Yards really relate to 33 to 24 fills difference (37.5% error)? The former is almost negligible, the latter monumental.

The two can live along side each other in perfect harmony without picking holes in someone else's work.

Again, I’m not ‘picking holes’ or ‘belittling’ anything or anyone – simply pointing out that an error (a correctable error at that) exists. The more serious point is that Rich (not Rob, sorry), having admitted prior knowledge of the essential Van der Waal correction, failed (for whatever reason) to make said correction and released the flawed spreadsheet anyway. If you’re not bothered by that then perhaps you don’t understand the problem or my concerns.
It may have been done quickly … it may have been for a good and worthy cause … but, when all is said and done, it’s just plain wrong.

This thread's sole aim was to provide FREE tables and charts to guide those folk who like that sort of thing.

FillCalc is free too.

ATB
Dave