I just purchased a new 16" RRA flat top upper and an Eotech 512.
I am attempting to boresight the 512 and as currently mounted, it will require substantial correction to zero.
Any advice on the proper way to shim up the rails to get closer to the rough zero would be appreciated.
Right now the sight appears to be low and left?
If this is not a job for an amateur, can anyone recommend a good AR smith in the Houston area?

thanks
TEXJOY

Thanks for the response SMG.
I'll take it to the range Monday.
I was just going by the instructions which recommended minimal use of  internal adjustments.
This is my first RRA upper and they seem to have a good reputation for being straight and square so hopefully internal adjustments will fix me up.

thanks
TEXJOY

I don't think you can boresight an eotech because of the fact that you do not need a cheek weld/proper head position/wherever the damn dot is is where the round hits...... because of that the reticle would be all over the place but still be correct (I would think)..... Take it to the range and shoot it- that's the best way...

FWIW My 552 was no problem- mounted up, took to the range and didn't need any adjustment to be on target (soda bottle)....

-Roth

Nuc
I'm sure you guys are right, but I was just going by the fact that I boresighted the ARMS 40 and when I mounted the Eotech it wasn't even close.
Shouldn't the dot be somewhere near the top of the front sight post?
My thought was that at least the windage would be close.
Also, the factory recommends boresighting.
I'm new to holosights, but not to AR's or setting up scopes.
Like you guys said, the best way to find out where a gun shots is to shoot it.

thanks
TEXJOY

Went to the range Monday.
Had to go to the 25 yard line to get the Eotech on paper.
4 inches high and 4 inches right at 25 yards.
Many clicks later,gun zeroed.
Back to 50 yard line.
minor adjustment to zero.
put 10 rounds into the 1" bullseye.

Flipped up ARMS 40 . The ARMS required 2 clicks of windage and 1 click of elevation on the front sight.
10 more rounds into the bullseye.
Sights are cowitnessed and I'm a happy guy.

Since the Arms was so close to zero, I'll "assume" that the rear of the rail,the barrel and the front sight are straight and square and that the Eotech was not.

Does it make any practical diffierence with the 512 being this far from center?
It's a bad thing in optical scopes, but I'm new to holosights.
The manual doesn't recommend this situation.

Access to the control buttons is limited by the BUIS.
This could be a problem in changing light conditions.

All in all a great setup, we'll see how it's doing after a few thousand rounds.