I recently bought an EOtech 512 which I had managed to convince myself that I would be able to share it between various AR's and a FAL carbine (obviously re-zeroing between calibers).
Now that I have it mounted on my FAL, I don't think that I'll be moving it around. Maybe if I had a Larue or Accucam mount I could get away with sharing it on the AR's but definately not between the FAL and AR's.
So has anyone been lucky enough to be able to share an optic have it remain zeroed between different rifles?
Didn't work for me. Course, I didn't have a Larue mount or anything fancy like that, but my 512 was off by close to 6" at 50yds when I took it off my 20" A4 and put it on my 16" mid-length A4.
I doubt you'd have the same zero if you had 2 identical rifles, let alone if you throw in different barrel lengths, different manufacturers, or different calibers.
If it does zero with more than one rifle......go buy a lottery ticket