would you say pretty much useless for a 20 inch barrel in 308? Trying to decide between it and a xotic scope. I'm going with one of the two it all depends on whether this ballistic mildot is worth anything.
Here is my take. IF you want to use the ballistics portion, you'll need to find a load out of your 20" that will match it really close. Even if its just "semi" close, it may be worth it.
Now, the thing I like about this reticule is that you lose NOTHING of the functionality of the mil-dots. As the distance from the fat stadia on bottom to the crosshairs is the standard 5 mils, so you can still mil everything from 1-10 mils like a normal mil-dot reticule. BUT, you have the advange of a ballistic compensating reticule if you decide to use it. I like the idea and especially the fact they preserved 100% functionality while adding a possible useful feature.