Charge discrepencies

So I've been tinkering and field testing for several hours now, and the formula I edited it to has been working for me 100% within 10-20 points of damage. On 5-charges. But when I drop down to 1 charge. Everything goes haywire and the theoretical values I get from punching in the numbers doesn't even come close to what I'm getting for field testing. It mostly comes to the distance portion, whenever I attack at full distance (r1) I deal 83.3% of the calculated max, based on the max value observed after many trials, but at point blank I hit slightly above still, at about 104% of max damage. I stripped down most of my enchants, excluding max damage enchants, talent bonus (11 water alchemy) and god's feather title (10) and ended up with a calculated damage of 516 max for a single charge with 836 mana. My additional damage contribution was 60.7.

I'm really starting to get kind of annoyed by the way my single charge math with alchemy doesn't actually work out when my 5-charge formulas are always down to a T. I did however find where battlefield is calculated in water cannon. At least for 5-charge.

Edit: So I figured out what is going on. Depending on the number of charges you have, distance affects you differently. So, with 1 charge, you would deal 80~100% of your damage based on your distance from the target. At 5-charges, this becomes 100~120% the steps in between all differ as well, but it seems to be approximately 20% spread between full distance and right up in their face, so I want to say 2 charge would be 85~105, 3 would be 90~110, and 4 would be 95~115, but my data with charges shows 98~118%

All in all it's way more complicated than I thought it was going into it >.> but at least my calculations aren't off, because these adjustments have allowed me to pin-point my maximum damage spread based on distance for each number of charges. Only calculating for max though.