I believe Bkondeff is referring to the 1600B apparently adding in temp and pressure to modify the EHR calculation. I was unaware it did this but found it when digging deeper. If you're shooting 1000 yards that may work but for an archery guy it's bad news. Since the 1600B EHR doesn't function under 100 yards it's a moot point for archers.
Allan, Looking back at your angle cuts on another post, it appears the 1600B is doing something because the cosine of 25 degrees at 325 yards would result in a shot at 294.5 yards rather than the Leica at 289. For a rifle, that may be the preferred method however.
Your post I referenced ( Leica 1600 LRF: actual use?
Bkondeff, thanks for pointing that out. I hadn't seen that in the manual till I read a little closer. I was typing while you posted..