@MarshallDodge - I’ll play my hand first: here’s the data for conditions I shot in at the SAME RANGE LOCATION between Dec 22, ‘22 and Aug 19, ‘23. It wasn’t quite -10F, but it WAS -6F back in December, and last weekend it was 95F, conditions which meant air density changed considerably, pushing the Density Altitude (relative air density corrected elevation) changed from -1500 feet to 3900 feet. (Of note: During the coldest winter months, I keep my magazines in an inside pocket with a handwarmer to ensure reliable ignition, and ensure my velocity is less influenced by the environmental temp).
That change in environmental conditions meant a change in Point of Impact at 600 yards of 3.3”…
This is shooting Berger 105 Hybrids over Varget and CCI BR4 primers out of Lapua brass through a Bartlein barrel, which delivers ~.1-.4” 3-5shot groups with 6-9fps 10 shot SD’s - there aren’t “better components” or ammo to be had or made.
But this is why BDC reticles don’t actually work in real world, changing environmental conditions.
BUT, that is using highly efficient 6mm Berger Hybrids with a proper long range cartridge. Comparatively, here’s what my 73ELD load (also over Varget) would be doing on this hot summer day vs cold winter morning, acknowledging that the 223rem being described isn’t quite as good of cartridge for long range shooting as is the 6mm Dasher… as you’ll note for 223rem, there is ~6” more drop at 600 yards, nearly a full MOA, when flying through the more dense, cold air, than flying through the thin, hot air…
So what is proposed here is that THIS reticle below is valid for delivering precisely 14.4 and 15.4moa shots, while its reticle reference ends at 11moa and 14.4-15.4moa hold reference will fall within the wide bar of the exterior frame - where the reticle itself covers 2.4” at 600 yards… (of note, if this reticle rendering is correct, 14.4-15.4moa won’t even be within the field of view at the bottom of the scope at the reference magnification. The shooter would have to zoom out to even see the target in the FOV.
This is why and how BDC reticles don’t actually work for precise, long range shooting in variable environmental conditions without a lot of extra work to manipulate SFP magnification to align aiming points with distances - changing your field of view… better to simply dial the turret and independently control your FOV… and of course, MUCH better to use a proper graduated reticle with more reference and use it in an FFP optic…