A better zero?

Depends.. for my r9 in .177. Dead on at 10m is just high at 30y and just low at 50 . With cphp. I think i got a resent pic of that if i aint deleted it. The 30y rise is almost equal to the 50y drop. ( Using stock iron sights, no optics)

Different pellets may give different result. Like more rise or drop or just flatter,ect. Its best to stick with one you found best or like and stick with it and know it well.

You can make a simple range card by using a simple holdover notation method by yardage. I go by every 5 yards. Data can be collected using inexpensive steel spinners set at each measured distance. You can use the same spinner and a can of cheap spray paint to refresh and read your hits.

For a second focal plane (SFP) scope, where the reticle size does not change with scope magnification, the holdover data will only be good for one magnification. In your case, starting with the graphical holdover plot you made, you could standardize on 12x magnification If you like it for all around use. I use 10x.

If you change your magnification to something different, your holds will change. In this example, if your range card data is for 12x:
1- Doubling your magnification to 24x with require doubling your hold value.
2 - halving your magnification to 6x with require halving the hold value.

I count each round dot on the reticle as 1. Tic marks between dots are 0.5. your eye can easily estimate 1/4 or 1/3. On your reticle, it looks like the spacing of the tics inside the long rectangles is equal to 1 mil dot. You will need these for your 5 yard hold point and long distances

Aim points *below* the center cross are positive, as they add elevation, and are called holdover.
Aim points above the center cross are negative, as they reduce elevation, and are called hold under.
Your standard data set is for horizontal shooting only!
Your hold values will shift more negative (holdunder) when shooting a high angles up into trees or downhill.

So taking your data and putting it into simple tabular form (ND means no data, - means zeroed/center cross aim point):
TX200 HADES 10.34 786 FPS
SCOPE:ND@12X SCOPE HEIGHT:ND
Yards/hold
5/ND
10/+3
15/+0.5
20/- (first zero crossing)
25/- (I suspect closer to -0.25?)
30/- (maybe also -0.25?)
35/-
40/- (second zero crossing)
45/ND
50/ND

This is a scheme I came up with, hope it helps you.

Here are a coupla pics of my range cards. Some are just notations using a sharpie on painter's tape.
The ballistics app Strelok Pro will make a table for you. It uses Up/Dn notation for holdover and hold under notation instead of +/-. I made a screen shot of it, printed it to the size I wanted, laminated it with tape, and taped it to the stock. That scope happens to be First Focal Plane (FFP), so the data is good for all magnifications and there's no magnification notation on the card.

Some people put the card on the scope bell, or just on a card. You could put it on your pellet pouch if you don't want to stick anything on your stock. It has to be very handy though for hunting/pesting quick reference. If you only have one rifle and use it often, you will quickly memorize the hold for each range, but once you have more than one gun like many of do, or start getting old, again like many of us, you'll want a range card to refer to.




GL,
Feinwerk

yes, an ideal zero takes advantage of the curve and 'skims' it to give maximum point blank range where you can aum dead on and hit within a reasonable spread ... youll find theres another zero further out with a close sight in depending on projectile speed, likely around 45ish ...

20 yards is a good first zero point for a medium powered air rifle. This often gets you a second crossing/zero point at 30 or 35 yards, very useful.

You can manipulate it to get the maximum point blank range where you have minimum hold over and hold under at your most often used distances.

Note that your range card data will change with different height scope rings. You can explore trajectories using ballistics apps to see for yourself. If you don't know about this, it's a little tricky but you need the measurement from the center of the scope to the center of your barrel, which is referred to as the scope height. The app will usually also ask for your ballistic coefficient for your pellet. If you cannot find that in a lookup table in the app or elsewhere on the internet, and you do have your scope height and velocity, you can take your empirical data and manipulate the ballistic coefficient value until it matches your actual results at each range.

Feinwerk

since the pellet arch's their are two points of intersection to the straight line of sight. their is a thread where this is expertly explained .

For me That card thing for a example like for 100y at 10m my shot should be 5" high of the aimpoint .. also if you draw a stright vertical line you can do a windage check if your not dead on the line as well. Saves wasting pellets caues os going to be pretty close . Then maybe fine tune clicks Everyone's got a thing ya know.

There are many ways to do it. I prefer scope tapes; I make them using Adobe Illustrator and tape them onto the turret.