There are a lot of new shooters out there whose first introduction to firearms ownership is the AR15 variant rifle. Many of these owners will skip iron sights completely and get a flat top rifle and mount some sort of optical sight, either scope (telescopic sight), red dot, or reflex optic. But others will still opt for iron/metallic sights, whether it be the standard military A2 design or some flip-up style sights (i.e. BUIS – Backup Improvised Sight).
Some of the iron sight AR15 owners end up doing reading on the Internet and stumble across references to the military battle zero, or battle sight zero. The concept of a battle zero is that you zero the sights for a specific distance such as 200 or 300 yards or meters, and that same zero will coincide with a zero at 25 or 50 yards. The United States Marine Corps M16 operator’s manual instructs personnel to zero the rifle to 300 meters, which has a trajectory crossing of approximately 37 meters.
Well, when you take a bunch of new gun owners with brand new AR15 rifles and they discover this information, they immediately become enamored with the concept, especially when they see that “the Marines are doing it.” This is when you see a bunch of people posting in Internet message boards about how they went to the range to zero at 25 yards and are wondering if this zero will translate to a zero at 200 yards, or a 50 yard zero will translate to a 200 yard zero, etc. Or someone will post about how they zeroed their rifle to 200 yards and isn’t properly hitting center at 50 yards.
If you are one of these people, you need to stop. Zero your rifle for a specific distance. That’s it. If you want to shoot at another distance, zero your rifle at that distance, too. If you want to shoot at another distance again, then zero your rifle for that distance, as well. The concept of a battle sight zero is flawed for what most of the people I see online that are “having issues” with it are trying to use it for.
- The battle sight zero is not supposed to be 100% accurate. Meaning: If you zero an AR15 with a center hold zero at 300 meters so it’s holing out the X-ring, it’s not going to guarantee that it will be holing out the X-ring at 36 meters. It’s most likely going to be hitting an inch or more high or low of the X-ring at 37m. Do not expect precise zeros at close range. That rifle was zeroed for 300 meters. That’s it.
- Ballistics vary based on many factors, specifically the ammunition used. I constantly see people who try to adopt the the USMC battle sight zero and use something other than the military issued M855 5.56 NATO 62gr ammunition. Most are using some commercial off-the-shelf ammo made by Remington/Federal/Winchester/PMC/Wolf/etc that they bought from Wal-Mart. All of these factory commercial cartridges vary in components (bullets, powder – weight and burn rate, primers, brass), so almost all will not shoot with the same ballistic characteristics as the US M855 standard infantry round. And don’t get me on the issue of external factors (temperature, humidity, barometric pressure).
With that, people need to ask themselves, “What am I trying to accomplish?” Are all you doing is target shooting? Then why rely on a battle sight zero in the first place? Just adjust your sights. That’s why sights come with adjustments knobs. So you can adjust them! “Hey, I’m consistently shooting 2 inch groups at 200 yards, but the group’s center is 2 inches low from the X-ring.” Then adjust your rear sight 1 MOA up on the elevation knob! It’s not hard to turn a rear sight knob.
Are you trying to play war or post-apocalyptic scenarios? Well, then just zero for 200 or 300 yards/meters and accept that you’ll have some trajectory cross at 25 or 50 yards/meters and be happy. Just don’t expect that close-range ‘zero’ to be 100% precise. It’s not called a “battle sight zero” for nothing. There’s no doubt you’ll hit the target at 37 meters. Just don’t expect 100% precision.