I am looking to purchase an Aimpoint for my AR and have two questions-

What are the advantages/disadvantages of the 2 MOA dot vs the 4 MOA dot?

Is there really an advantage to those cantilevered mounts which place the Aimpoint as far forward as possible on the rifle?

Thanks for any help!

Liberty,

First, dot size.  The only real difference is how large the dot appears on the target.  At 100 yards a 2 MOA dot  covers 2 inches, the 4 MOA, 4 inches.  If you are plinking then a 2 MOA dot will allow you to shoot a little more accurately.  The down side is the 2 MOA dot is smaller and can be more difficult to see.  Other than the EOTech most combat type red dots use a 4 MOA dot.  I have a CompM with the 4 MOA dot and I can ding a steel plate, 8x10 inches, out to 300 yards with no problem.  I can also double tap a target inside of 20 yards quickly because the dot is very easy to see and put on the target.

I can not give you any info on the cantilever mounts as I have never used one, but my CompM is on an ARMS #39 and it is mounted right behind the front sight with just enough clearance for the front cap to open.  The advantage to placing the optic so far in front is it will not hinder your view as much.  Red dots are designed to be used with both eyes open.  Your field of veiw using the optic and just looking down range are the same.  By moving the optic out front it will appear smaller, but still have the same size dot, and not clutter your vision as much.  I found that mounting my red dot near the front sight base works best for me.  I have tried it in several different positions, including on the top rail above the carry handle, and settled on out front.

Just remember, what works for me may not work for you.  The best advice I could give is experiment with what you have, look at what others have, if they will let you handle and shoot it even better.  Fit your weapon to your mission.

Sarge

2" or 4" at 100 yds

cowitness option with and a2/a1 upper and better field of view with scope mounted forward or less of your view obstructed surrounding the optic

+1