2.5-10x56 trijicon accupoint on AR?

a larger objective actually has nothing to do with larger FOV. 

It will be brighter in low light at a higher mag than the 3-9x40 scope

But as far as cleaning the objective.  That shouldn't be an issue as long as you use a typical height AR mount. 

Rifles are like violins. They need to fit if you are to play well. Every single time i tried to shoot from field positions a rifle with a large scope representing 1/4 of the total weight of the rifle positioned well over the bore line i found that the rifle had a poor balance and i shot poorly. 

The 2.5-10x56 is a nice scope if you plan to use it in very low light.  It is a bit heavy and on most ARs, it would not be my choice.  However, if this is for night use, then it is a good way to go.

Old thread but still relevant as I am in the same position as shooter2440. The search feature answered a lot of questions. Since this is a 4 year old thread is there anything new that someone would recommend for the same purposes? I'm leaning towards the Trijicon 3-9 with a triangle post. I need a different set up than my Leupold 1.5-5x24. 

I used to use that set up on an AR-10 308. While very effective, the cons outweigh the pros. AR-10s are heavy. With that scope, their even heavier. My AR-10 was also “boxy” with sharp edges everywhere. Uncomfortable to carry around all night. I know that people use AR-15s for hunting hogs but I prefer something light, accurate and powerful nowadays. I use a Sako A7 in 270 WSM with the Trijicon 3-9X40 mentioned. I prefer the mildot reticle. I has the smallest illuminated dot. That’s a factor when shooting at night. Both the brightness of the illumination and the physical size of the illuminated area can be difficult to see past,  and line up on your target. Pic is from 2013. I killed a lot of boars with that rig. Seven years later, I still kill my share but try not to suffer as much doing it.