Running a couple 40grn @1250fps loads through my calculator with a 50 yard zero and and the optic height of my specific firearms... your assumption for 25yrd & 75yrd could be wrong, or you could be right. It’s not correct for any of my firearms with any of the loads I simulated, but it is close enough that maybe my environmental inputs or optic heights versus yours could make the difference. I will say, in my experience with 22LR and LR/ELR shooting, ammo is not universally similar enough to use generic data, certainly not similar enough to use a common zero for multiple loads without rezeroing, and frankly, 22LR is just too sensitive to environmental and wind conditions to use any short cuts.
The big downside - trajectory data from one load to another is incredibly variable. The BC’s of 22LR are so low, there’s a huge difference between POI/trajectory even when the loads leave at the same velocity.
The math for scaling your holdovers is very easy: (reference mag) / (actual magnification) * (calculated hold) = (actual hold). BUT... since you don’t have regularly spaced dots, that’s not terribly valuable... if your calculator/DOPE card says 3.1moa for 87 yards, and then you have to do the scaling for 8x instead of 7x to know what your first and second dot represent, and THEN estimate where your hold should be between them... eh... it’s just not worth the time...
My personal recommendation is to download StrelokPro if you don’t already have it, use their existing ammo data (they include known specs for a LOT of 22LR ammo brands and models) or input your ammo parameters, and build a rifle profile with your exact optic height and your Drop Zone 223 reticle (which IS included in StrelokPro’s database).
From that, you can use either or both of two different techniques:
1) With phone in hand behind the rifle, input your range, wind speed, and magnification and it will give you a point of aim to achieve impact.
2) Before venturing afield, make a data card for each load you might shoot for a few relevant density altitudes, and scroll through various magnifications in the reticle page, recording the ranges each dot represents at each magnification. So later in the field, you can range your target, pick a magnification, and then read from the table the most proximal hold position. Using the table pictured below, if I ranged a rabbit at 125 yards, I might dial to 7x and hold dead on with the 3rd dot, or dial to 9x and hold half way between the 3rd and 4th dot to make the shot. Note, you need to include additional data for wind corrections which are not pictured here. Also note: I know I won’t shoot 297 yards at 3x with a 22LR, so I typically make the text in what I consider to be “irrelevant data” boxes smaller and grey instead of full black print or even eliminate it from the table to simplify my data card. For my use, I might not even include ANY of the 3-5x data which correspond to more than 150yrds, as I simply won’t shoot that low of magnification that far out.
A THIRD option you have is to slide your magnifying turret in StrelokPro to make one of your dots align with the field measured target range, then you’d simply dial the scope to that magnification and hold the respective dot on target. Not my favorite option, but it does work.
