Bought my first AR and now I am looking for the perfect optic to top it.  Looking at the AIMpoints or the Eotechs.  My question is what would be a good medium range optic for 100 to 300 yds?

I have both. From my experince, the EOTECH has a slight edge for CQB due to the large reticle around the dot and larger sight window. I have both sighted in at 200 yds (my range does not have 300 yd facilities), both work great.

out to 300 yards an aimpoint will "suffice"

But

In my opinion, a low powered variable (1x3, 1x4, 1.5x6, etc.) is ideal for the AR platform.

Weaver makes a great low cost 1x3 with good optics (low cost and good anything are 99.9% of the time mutually exclusive in the optics world).

Millett has a 1x4 although some users are reporting problems.

IOR Valdada

Leupold Mk4 MRT

US Optics

Schmidt Bender Short Dot


list runs least expensive to most expensive.  

On my AR I have YHM flip up front and rear sights. What mount would work on the low power variable so that I could still use my flip up sights?

Quoted: On my AR I have YHM flip up front and rear sights. What mount would work on the low power variable so that I could still use my flip up sights?

you can't.

your BUIS will rest under the ocular.  If you have to transition to irons, you'll have to remove the scope/mount.  This is one reason why LaRue and ARMS throw-lever mounts are so popular.

BTT

Quoted: Bought my first AR and now I am looking for the perfect optic to top it.  Looking at the AIMpoints or the Eotechs.  My question is what would be a good medium range optic for 100 to 300 yds?

The IDEAL optic for 100-300 yards is NOT an Aimpoint or an EOtech.  You will want magnification for those distances unless your only desire is "hit the target somewhere."  You will be very unhappy of you go shoot for groups on paper at 300 yards with one of those.

How small of groups do you want to put up?  How small of targets?  IMO you need at least 4X magnification to shoot small groups consistantly at 100 and up and could need 10X for a minimum, depending on your eyes and desires, at 300.  You will want a thinner reticle as well if you are desiring sub MOA performance at 300.  A 4MOA Aimpoint with a 3X magnifier will not make you a happy camper at 300 yards if you are wnating small groups all in the bull.

Quoted: On my AR I have YHM flip up front and rear sights. What mount would work on the low power variable so that I could still use my flip up sights?

The only options are the dot style sights, Aimpoint and the EOTECH's for cowitness.

Just so you know...I have a low power 1-4 scope on my flat top AR with a A2 FSB...I dont see it. When I take it off, install my aimpoint and use my ARMS 40, I see it.

The aimpoint will be good to go out to 300.

Let us know what you get.