View Full Version : AR15 zero for scope AND irons

November 16, 2012, 04:45 PM
I've read a lot of threads about the "best" zero but haven't seen many on scope and iron sight zero.

What range should I zero my BUIS for?

3X scope?

November 16, 2012, 05:22 PM
You're going to get more than one way to do this, because individuals have different scopes/irons, different needs, skill levels... you get the idea.

I will, as a general rule, set BUS to zero at 50 yds with a 55 gr. bullet. With this setting, other than at the muzzle, you'll never be more than 2" above or below your POA out to 270 yds.

Scope? Hard to say. You don't say what you have for a reticle... the functionality of the reticle tends to establish your best zero.

November 16, 2012, 06:22 PM
I will, as a general rule, set BUS to zero at 50 yds with a 55 gr. bullet.

Same here. A 50 meter zero puts me about 1" high at 100 meters and back zeroed at 200. Using a no-magnification red dot I can put rounds on paper plates all the way out to 300 meters with this zero, and can still keep them in a torso sized silhouette at to almost 400. So 50 is definitely my preferred zero, though I'd recommend you also verify your zero at 200 as well.

November 16, 2012, 06:37 PM
Look for a video about zeros by Travis Haley on youtube. He displays the results of a half a dozen different zeros for a 5.56 AR from 25m out to 500m. From there you can decide which zero is best for you.

50m and 300m zeros seem to be the most popular.

Crow Hunter
November 16, 2012, 07:29 PM
No matter what you do, you need to actually check your zeros and where you actually hit. Don't just rely on ballistic charts. Every gun/optic/round combo will be slightly different.

You really need to check it at all the distances you plan on using it and make yourself a DOPE book. (Data on previous engagements).

November 16, 2012, 10:37 PM
Thats what complicates things as well.

Would like to shoot cheap 55 gr rounds and the 77 gr as well.

Scope is a Nikon 3X with BDC reticle. http://www.nikonhunting.com/products/riflescopes/p-223/3x32_BDC_Carbine/8496

Says 200 yard crosshair. So need to zero for 200 yards.

November 16, 2012, 11:27 PM
Would like to shoot cheap 55 gr rounds and the 77 gr as well.

BDC reticles are really only intended for one load, because the distances and drops are going to vary from one load to the next and even from one rifle to the next. That said, Nikon has software (http://www.nikonhunting.com/SpotOnRegistration/) you can use to run the drops based on different loads as long as you know or can estimate the velocity of your ammunition. So there's no reason you couldn't have data for two different loads if you want, as long as you know the drops will be different. And as far as zeroing goes, you can still zero your crosshairs wherever you want and then use the drop points accordingly once you figure our where they are approximately. I'd agree with Crow Hunter though that one way or another you'll want to actually verify your zeroes after you estimate your distances.