I’m mounting an Aimpoint M4s on an AR-15. What are some considerations in regard to eye relief. The only thing I could find in the Army marksmanship manual is to allow enough distance so the shooter can maintain some situational awareness without having the optic so close so as to block some vision.
Mount it somewhere in the middle of the gun that you feel gives you the best possible field of view, not eye relief, per se.
Experiment. Run it on a timer. Check the balance of the weapon. Everyone has their own preference, but there are no eye relief issues with a 1x Aimpoint.
+1. Eye relief is primarily an issue for magnified optics, not for 1x optics.
Aimpoints have infinite eye relief, so it just comes down to preference.
I tend to run mine near the middle of the gun at the end of the rail on the receiver.
Here’s a link to one point of view on the subject;
http://www.usshootingacademy.com/CM_Files/FIGHTING%20THROUGH%20THE%20RING%20by%20Erik%20Lund.pdf
While Lund favors having the optic as far rearward as possible, noted trainer John Farnam favors having it as far forward as possible.
The use of piggy-backed magnifiers or night vision units may dictate where the dot sight is mounted as well.
It all boils down to what works best for you.
Rosco
If you are weak eye dominate, mounting it further back instead of the usual mid to well forward helps some when shooting both eyes open.