I moved an older pre F version EOTECH from an M4 clone where it worked perfectly to an AR Pistol with 7.5 inch barrel.  At 25 yards I am shooting 3-4 inches low and I have run out of elevation adjustment.  

The wheel turns but no longer clicks and their is no change in bullet strike.  I moved the wheel several turns once the clicking stops and nothing.  I stopped out of fear of damaging something and if POI didn't move with several complete rotations, what was the point of going further.

Anyone else have this issue?  All I can figure is that a normal rifle length barrel moves enough under recoil while the bullet is still in the bore that it hits higher on the target.  That is why I had no issues when it was on the M4.

I was going to try shooting at 50 yards to see if I was too close given the bullet trajectory, but then my batteries died and I had forgotten an extra pair.

try turning it one way or the other for quite a bit. i had the vert adj. do the same thing. i think you went past the max like i did and screwed the adjuster right out of the "pot" or whatever. i was about to send it to eotech, but i turned it one way a good deal an caught the pot again.

I don't rmember the maker,but Brownell's sells a small shim for scope mounts that have run out of adjustment. IITC it can be place to raise or lower front by 5 degrees.it's like a small wedge