Wife bought me a Burris MTAC 1x-4x for Christmas (Primary Arms).  Finally mounted it on my AR and went to sight it in.  No matter what position the rheostat is on, if I fire once the reticle shuts off.  If I lightly touch the battery compartment cap with a fingertip it then turns back on.  The cap is screwed down securely, battery connections are clean.  Any idea what might cause this?  I hate to have to send it back, what with the mad frenzy all gun-related sales are going through right now.

Well, it sounds like an intermittent connection failure somewhere.  The way I see it, you have 2 options:  1.  Slightly bend the tabs or spring that put pressure on the battery in order to increase holding force.  2.  Send it back.

Yeah I'm going to try the battery tabs tomorrow, that was my first thought as well.