I know the consensus is that locktight goes on the BUIS, but what about on my ACOG/EOtech?  Should I use locktight on those as well?

Also, where does one get locktight?  Lowes?  Home Depot?

Thanks for ya'lls help.

Not the ACOG-

Put it on the EO tech.  (use something weak like low or medium strength loctite- something that doesn't need to be heated to dissassemble.)

Every screw (including ACOG base to houseing if you are changing one out) that goes on a rifle needs loctite.  

That doesn't include [obviously] the barrel nut, or the pistol grip screw, but some guys like to do stock nuts in absence of peening them on.  

I haven't done the peen or loctite yet and haven't had one come loose (I just torque it heavilly; like 30+ft lbs.)  

Ace hardware, advanced auto parts, NAPA, etc.  Those guys should carry loctite.  Sometimes Walmart, and sears tool centers

I do not think you should loctite anything that may need to come off in a pinch (ie Eothingie) - unless you are loctiting to a larue mount.  There should be no need - the eotech will stay tight if mounted correctly.  I am using the RRA Dominator and loctited it.  My eo is dry to my Dominator.

As far as the BUIS - I always blue loctite.

Wouldn't something like plumbers teflon tape serve the purpose of  preventing screws from turning. Seems like a good alternative for screws that you don't want to use Loctite on.

Blue (not red) Loc-Tite on screws you want to stay put but may want to remove later!

EDIT to add. Wal-Mart for the best price.