I was pretty dead set on getting a Nikon 3-12x M-223 scope for my new 16" .223 AR, but after reading around in the forums I'm not so sure anymore. I'm looking for an optic that will allow me to shoot tight groups at up to 400 yds but also give me the option of going out further. Most of the threads are concerned with CQB/tactical optics with lower magnifications, but I'm more interested in practicing long distance shooting. The M-223 scopes seem to be alot for the money, but now I'm starting to think about increasing the budget to get a more versatile and higher precision option.

First of all, is 12x enough (or perhaps too much) magnification for the distances I'm looking to shoot?

Other than the Nikon M-223's, I've been looking at Nikon's other offerings (Monarch, etc) as well as several Leupolds and the Vortex Viper series but haven't found a local shop that carries one so I can see it it person. I did compare the Leupold Mark AR to the Nikon M-223 in person, and I have to say the Nikon seemed to win hands down. It was much clearer and at maximum magnification it seemed to have a larger exit pupil diameter (less "tunnel vision"). I've also started looking at some of Trijicon's offerings and really like the TR22, but I'm not sure the extra money would be worth it or if the 10x magnification would be enough.

Please offer your suggestions/opinions, I'm pretty new to the rifle game so I know there's still alot for me to learn.

Well what are you going to be shooting at?  At 400yds, if you are shooting at a man sized target, you can use iron sights and do fairly well.  If you are shooting at a target the size of a softball, you won't even be able to see it at 400yds without a magnified scope of some type.

Varmint hunting might be somewhere down the road, but for now I'm just looking to practice on paper targets.

If you're a decent shooter, 1x for every 100 yards will give you 1-2 MOA if the rifle and ammo is on par.



5x for 500 yards



10x for 1000 yards etc.
There are plenty 1000+ yard kills in Afghanistan and Iraq with a 10x optic.
For 223 I see no reason to go further than 3-9x scope unless you have horrible vision.
Edit to add:





A 9x cheap scope is about  as useful as a 5x scope with good glass at distances over 300-400 yards. If you get a 3-9x high end Leapold, US optics, Nikon, etc you'll never be able to out shoot the scope with 5.56. (if you have bad vision you might need more though...)



Now, if you're shooting prairie dogs at 350-400 yards it'll help having 3.5-12x, 4-16x, or 5-20x to see the stupid little things.



But something the size of a fox or coyote you'd be fine with 3-9x.



 

Good information Forgetfull, thanks! When you say "high end", what price range and/or models are you speaking of? I was originally ready to spend around $400 or so with the mounting hardware, but I'm willing to jump to $600-700 if it'll make the scope that much better.

High end would be $1,000+

As said above, true "high end" is $1000+ but something like a Leapold Mk 3/4 for cheap or lightly used would be fine. I'd try and spend over $5-600 but I can understand not wanting to spend over 1000$ for 223.
~700 should by you a good scope (used or new).
Take a look at this thread and article if you haven't seen it.



http://www.ar15.com/forums/topic.html?b=6&f=5&t=186971
If you want to read the article in the thread click on the three links since the links have been updated more than the copy and pasted thread article.
You're intended use and targets can dictate how nice/expensive you need to go. Military vs. hunting 6 times a year vs. competitive shooting. But like I said, clarity of the glass helps out so so much. Buy as best as you can afford. If you buy a 1000$ scope and keep it for 25 years that's only $40 a year. Optics are a great investment.



 

IMHO a 1-4 tactical scope will be fine for out to 400 yards.  Really any thing past 400 yards is not really in the ball park for 223/556 if your hunting anything other than paririe dogs and ground hogs.  And yes 12x is way too much unless you're benchrest shooting.  A high power scope really limits your feild of view and your scanning ability.  If you are just target shooting by all means 12x will be great because you will know where your target is.   A 2.5x10 would be a good choice for a REPR type rifle also.  A scope really depends on what you want to do with your rifle.  Good luck hope this helps.

2.5-10x24 NXS.