Mine is the SBR and I was wondering which height I should be looking at. Haven't had a chance to swap any of mine around on it yet and figured I would just ask.

ETA most likely looking at a T1 or H1 rather than the bigger aimpoint if I go that way.

LT-152 co-witnesses nicely with the standard height sights. If you're using the fixed front, the sight picture might be a bit distracting.

The sight line is lower than an AR because of the low stock.  Also, the charging handle is pretty close to the underside of the top rail.  For both of those reasons, an Eotech isn't a good fit.  You'll probably be scraping your hand against the overhanging Eotech.  An Aimpoint is better.  I use an AD-68-L mount on my 556 and 551A1.  It co-witnesses with the factory iron sights, with the rear diopter in the "V" position.

I agree with every thing this member posted.

Question, how does the AD-68-l compare to the aimpoint factory low mount?

So I guess I should have clarified I will probably be going with one of the small aimpoints rather than one of the 30mm dots. Maybe I should put that PRO to use.

I had a T1 mounted straight to the rail on my 553 clone with the factory low mount and it cowitnessed perfectly with my Aurora sights. I swapped it for a RMR later on as I preferred the triangle dot.

Had I not had my sights installed the T1 straight to the rail with no irons would be very comfortable using the Sig SAN stock. You could even get one of those MFI low flip fronts to use as a point of reference then sight through the dead T1 tube as an emergency BUIS of sorts.

Are the aurora taller or shorter than stock?? How would the t1 line up with the factory sights if it was in its stock mount.

The Aurora sights are very close to Sig SAN height, which is much lower / shorter than the  Sig USA diopter height. If you are using Sig USA diopters you will need a riser or a taller mount, without it you will be sighting into the top of the T1.

Edit: But as I said earlier if you can live without a physical rear BUIS and you prefer to only use the MRD you could pull your Sig USA diopters, replace the front with a SAN height MFI flip and directly attach the T1 to the rail. That way you could have the nice low cheekweld on the SAN style folding stock and still have a flipable front post if you needed it.

If I did not have my Auroras that is the arrangement I would most likely be using... but that is mostly because I love the low cheekweld on the SAN style stock. The Sig USA diopters were designed with AR optics in mind and they just sit way too high for my personal tastes.

The AD-68-L is 1.1" above rail, the LT152 is 1.2" above rail.

If you want a Micro, AD T-1 CAS-V is probably the best choice as it sits 1.15" above rail.

Damn guys I really appreciate the help.

Does the RMR cowitness? With what mount?

+1 on liking the low sight line with SAN style stock.

Yes it does, perfectly fine with the Aurora sights. I have also pulled the rear off and used it with the hooded front sight to very good effect. To my understanding the Aurora front sight is the same (or very close) to the height of a SAN front sight.

I'm using the regular Trijicon RM33 two screw low mount bolted to a RM08G.

Aimpoint H1 in the HK height Larue mount works for me.

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