Learn how to zero your carry deal with AR with the A2 sight system — and why the 50/200 IBZ is the smarter selection for many shooters.
What Is an A2 Battle Sight Zero?
The A2 Battle Sight Zero (BSZ) is a factory-default zero setting for the M16A2/AR-15 A2 rear sight system. Out of the field, the A2 sight is configured for a 300-meter zero — the army commonplace. At that setting, your level of influence matches your level of intention at 300 meters with no holdover required.
However for many civilian and defensive use, the 50/200 Improved Battlesight Zero (IBZ) is a extra sensible selection. It provides you an almost flat trajectory from 0–200 yards — the ranges that truly matter in a defensive or searching context.
Why 50/200 As a substitute of 300?
The 300m zero made sense for army engagements in open terrain. For many of us, engagements occur inside 200 yards. The 50/200 IBZ retains you on paper at each distances with a minimal maintain, and the A2 sight system helps it natively — you simply should know the best way to set it up.
Mounted Carry Deal with vs. Removable — Know the Distinction
Earlier than you begin turning drums, know what you’re working with. The A2 sight geometry differs barely between fastened carry deal with uppers (like a basic M16A2 or Colt SP1-style) and removable carry deal with uppers (A3/flat-top with a detachable carry deal with). The removable deal with sits barely greater, which shifts your zero by a couple of clicks.

The desk above reveals click on changes from the 300m base setting. Each setups attain the identical zeros — you simply use totally different click on counts to get there.
Learn how to Set Your A2 Sight for a 50/200 Zero
This course of resets the drum’s baseline so your sight’s marked positions really correspond to right zero distances. You’ll want a 1/16″ Allen wrench.
Set the drum to six/3 – Rotate the rear aperture drum till it reads “6/3.” That is your beginning reference level.
Loosen the set screw – Use your 1/16″ Allen wrench to again out the small set screw on the drum. Don’t take away it — simply loosen sufficient so the drum can spin freely from the indexing detents.
Flip the underside drum up 4 clicks – Whereas holding the highest drum stationary, rotate the underside drum upward 4 clicks. You’re bodily repositioning the zero baseline.
Align the highest drum to eight/3 – Rotate the highest drum (the marked one) till it reads “8/3.” This re-syncs your reference marks to the brand new baseline place.
Tighten the set screw – Comfortable down the Allen screw to lock the drum in its new place. Don’t overtighten — simply agency.
Come down 2 clicks (fastened deal with) or 4 clicks (removable) – From 8/3, click on the drum down towards 6/3. Mounted carry deal with: 2 clicks down. Removable carry deal with: 4 clicks down. Reference the chart above.
Zero at 50 yards utilizing the entrance sight put up – Head to the vary. Hearth a gaggle at 50 yards and regulate your entrance sight put up solely — as much as transfer influence down, down to maneuver influence up. Don’t contact the rear drum. While you’re centered at 50 yards, you’re additionally zeroed at 200.
Watch the Full Setup
This video walks by the precise drum manipulation course of above. Value watching earlier than you hit the vary the primary time.
Backside Line
The A2 rear sight ships zeroed for 300m — helpful for army, much less so for everybody else
You may reconfigure it for a 50/200 IBZ with a 1/16″ Allen wrench in below 5 minutes
Mounted carry deal with = 2 clicks down from baseline. Removable = 4 clicks
At all times use the entrance sight put up for last zero corrections — not the rear drum
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