How do I choose between 2MOA and 4MOA Aimpoint model?

I have both, and prefer the smaller dot. You can always make the smaller dot brighter to make it more visible, but you can't make the bigger dot smaller and more suitable for relatively precise work.

i always prefer the smaller dot ie that is why i use the eotech, 1moa when the accuracy is needed and for bad breath distance the 65 moa cirlce is just fine.

for your needs the 4moa would do just fine. and if i wasn't going past 100yds then i would choose the 4moa. with that said, our army issued weapons back in the day had 4moa aimpoints (m68's) and qualifying which is out to 300 meters was easily done. not preferd but doable.

also if you want to make the 4moa a little more precise, then i suggest that you zero the tip of the red dot as your aiming point and not the whole dot. when you have time on a distance target use the tip, and when you don't impose the whole dot on the target and go to town.

Can't see the beer can

I asked a friend of mine about the one he chose. He has the 4MOA and wish he had got the 2MOA. The reason? The 4MOA totally covers the beer can. The 2MOA doesn't.

So if plinking is critical in your shooting, then go with the 2MOA.

If you can see it smaller dot is always better. Big dot = big groups.

For comparison, the 4MOA dot is a lot smaller than the width of your front sight post. It doesn't determine your group size-- the consistency of your hold does. Aimpoint, years ago, did extensive tests in the field and determined that the 4 MOA dot was the best "all around" compromise.

I get asked this same question a lot, and I usually recommend the smaller 2 MOA dot. As stated, you can always turn up the intensity if you need the dot more visible. For more precision in slow fire, turn the dot intensity down, so that there is no "bloom" around the dot, and you'll see the dot outline with much more clarity.

Possim has a very good point too, in that you can zero by using the top of the dot as your strike point, a bit like the top of the iron sight post. There are no laws requiring you to use the sight in any specific manner. When shooting at a round bull's eye, for group, I print targets so the bulls are green (contrasting with the red dot) and sized such that I can center the dot and see a green ring around it. That's just one option, but it's only good for that very specific situation. In CQB, by contrast, it's just not that big a deal either way. We shoot clays using a center-dot strike also. That seems to work out fine, and in any case, the strike point is constantly changing with the distance.

I've used both and now use the 4moa exclusively. All my shooting is less than 200m with the vast majority being less than 100m so I prefer the larger & quicker to acquire 4moa dot (I can still hit consistently at 300m if I do my part) and turning down the intensity a click or two provides a much smaller dot for max precision. If I were going to use a magnifier and/or shoot at 300m+ on a regular basis then I would go w/the 2moa.
Tomac

If we can adjust the dot brightness perfectly each shot, such that there is no flare or glare around the dot, theoretically a 4 MOA dot will cover a 4 inch diameter area at 100 yards. A 2 MOA dot will cover 2 inch diameter at the same distance.

Above information has been adjusted and is correct. Thank you, Omnivore, for calling my attention to the mistake.

Because of the flare around the dot, the covered diameter may double, even more. The more the flare, the bigger the perceived covered area.

I'd go for the 2 MOA dot anytime.

easyrider; 4 MOA is four inches at 100, 8" at 200. 2 MOA is 2 inches at 100, 4" at 200 yards, etc. One sixtieth of a degree with a radius of 100 yards. You can do the math-- 2 Pi R, convert yards to inches, etc.. One MOA comes very close to one inch per 100 yards.

A reflex dot, or a holo reticle, does not technically "cover" anything. It's superimposed on the fully visible target. The word you want is "subtend". Iron sights and conventional scope reticles "cover" part of the target because they're opaque and you're seeing with only one eye. The reflex dot is a different animal, just a dot of light in your regular field of view. Since you're usually using both eyes, you have your full, natural field of view, hence, nothing is obscured or "covered".

Omnivore,

Oooops, my bad. You are 100% correct. I applied the formula wrongly. Thanks for catching that one.

Perhaps I should correct my previous post so as not to mislead anybody.

i like 1MOA the best

aimpoint makes a compC3 2x with a 1MOA dot.