Category: Gun Info for Rookies
Though many shooters these days use some sort of optic on their AR-15 as their primary sight, having a good set of backup iron sights is still a really good idea. However, though they are similar in many ways, the backup iron sights on an AR-15 are slightly different from iron sights on many other rifles.
Here is a step-by-step guide on how to zero the backup iron sights on an AR-15.
Many of the “flat top” AR-15s on the market today come ready to accept a backup iron sight (BUIS) to use in case something happens to the optics on the rifle. While they come in a wide variety of configurations, the basics of how to use them remain pretty much the same.
First, ensure that your backup iron sights are properly installed and mounted securely to the rifle. If you are able to wiggle the sights with your hand, they are not secured properly.
Second, mechanically zero your backup iron sights. For the rear sight, ensure that the aperture is exactly centered in the housing. To do this, adjust the aperture until it is all the way to one side. Then, count how many clicks it takes to adjust the aperture until it is all the way on the opposite side. Divide this number by two, then move the aperture back that number of clicks.
Here is a step-by-step guide on how to zero the backup iron sights on an AR-15.
Many of the “flat top” AR-15s on the market today come ready to accept a backup iron sight (BUIS) to use in case something happens to the optics on the rifle. While they come in a wide variety of configurations, the basics of how to use them remain pretty much the same.
First, ensure that your backup iron sights are properly installed and mounted securely to the rifle. If you are able to wiggle the sights with your hand, they are not secured properly.
Second, mechanically zero your backup iron sights. For the rear sight, ensure that the aperture is exactly centered in the housing. To do this, adjust the aperture until it is all the way to one side. Then, count how many clicks it takes to adjust the aperture until it is all the way on the opposite side. Divide this number by two, then move the aperture back that number of clicks.
Assuming that you have a standard front sight, adjust the base of the front-sight post until it is level with the sight housing in order to mechanically zero it. To do this, depress the detent on the front side of the post and turn the post at the same time. You can use the tip of a bullet, a multitool, a nail or a specially designed front-sight adjustment tool to accomplish this.
After mechanically zeroing the backup iron sights, you’re ready to start shooting. I like to shoot at 25 yards, then move out to longer ranges after I adjust my sights. This saves time, ammunition and frustration in the long run by ensuring that my shots are at least on the paper. Don’t worry too much about the type of target you use. Almost any target will work, as long as it has a distinct aiming point.
Just like when zeroing any rifle, it is important that you shoot using a stable, supported position when zeroing your backup iron sights. Try to avoid supporting the rifle with your muscles and use a stable object like a sandbag instead.
From a steady shooting position, fire three shots at the center of your target at 25 yards (or whatever range you are shooting at). After firing your first group, check the target. Measure from the center of the group to your aiming point, and adjust your sights accordingly.
For most sets of backup iron sights, you must adjust the front sight to move the impact of the bullet up or down and adjust the rear sight to move the bullet impact left or right. As you can see in the photo above, turning the front-sight post clockwise will raise the point of impact of the bullet. On this same rifle, turning the rear-sight adjustment knob clockwise moves the bullet point of impact to the right.
However, different AR-15 variants will often have different MOA adjustment values. On some rifles, one click on the front sight will move the bullet impact 1.2 MOA (about 1.2 inches at 100 yards), while others will move the bullet impact 1.5-2 MOA.
The same goes for the rear sight, and you can expect one click to move the bullet impact .5-.75 MOA, depending on the rifle. The only way to be 100 percent sure with your rifle is to take it to the range and experiment with it.
Also, don’t forget that when shooting at 25 yards, you will need four times the number of clicks (4 MOA equals about 1 inch) to move the bullet impact the same distance at 25 yards as you would at 100 yards.
For example, assume that I shot a group at 25 yards that hit 1 inch high and 2 inches to the left with a rifle that has 1.25 MOA elevation and .5 MOA windadge adjustments. Since I need to move the bullet impact down and to the right, I’d rotate the front sight three clicks counterclockwise (round to the nearest whole number) and adjust the rear sight 16 clicks clockwise.
After making the required number of adjustments, shoot another group. If that group hits where you’re aiming, your AR-15 is now zeroed at 25 yards. If not, make the necessary adjustments to your sights and continue shooting until you have a good 25-yard zero.
Using the same techniques described earlier, you can now start shooting at longer range, if desired. Since you zeroed the rifle at 25 yards, it should be at least hitting the paper at 50 or 100 yards. The only difference now is that you need to remember that the number of clicks necessary to move your bullet impact at 50 or 100 yards is different than at 25 yards. At 50 yards, moving your sight 2 MOA/inch and at 100 yards 1 MOA/inch.
There is a lot of debate in the shooting community about the best distance at which to zero your AR-15. The correct answer all depends on the specifics of your rifle and ammunition as well as the typical distances at which you plan to shoot your rifle. For most people, a 50- or 100-yard zero for their back up iron sights will work great.
Regardless of what range you choose for your final zero range, after you’ve made your final adjustments, fire one last group to confirm your zero. If your group hits where you were aiming, you’re done. While you hope to never have to use it, a good backup iron sight will hold a zero for a long time.
I sat overlooking a beaver swamp, with a bait barrel full of fish heads and moose bones, waging war on the black flies. The temperature had risen to nearly 70 degrees that afternoon, and I was being eaten alive. I’d packed a couple of sandwiches and a can of soda for the evening vigil, and though I’d just gotten to my stand, I was hungry already. I had just unwrapped one of the dainties when I saw—for it did not make a sound on approach—a decent boar come into the bait site. Flies be damned, this was exactly what I was waiting for.
I raised the handy .308 Winchester and put one 180-grain bullet into his boiler room, turning the black bear into an infuriated beast, but a second bullet ended the affair. It was my first bear, and I was immediately hooked. I’ve spent much more time hunting for bears than actually shooting bears, but it’s a hobby I enjoy very much. That spring, among the beautiful lakes that make up the Quebec landscape, was the first I’d hunted big game here in the States, and it was something that would become part of my life. Let examine the reasons to book a spring bear hunt.
1. It’ll take to you to a different part of the world.
Much of the spring bear hunting is done in Canada, with our U.S. opportunities being in Alaska and a few Western States. A change of scenery represents an adventure—at least in my book—and for many of us, a trip to those areas that allow spring bear hunting can be a great time. I know that you need not ask me twice to begin planning a trip to a different destination, and more than likely, the country you’ll see will become a very fond memory.
2. It’s halfway to deer season.
It’s been quite a while since deer season closed—in most areas anyway—and if you’re like me, you’re starting to feel that itch. Yes, turkeys offer great sport and will always be a part of my spring ritual, but bears offer a reason to grab a rifle and experience a whole new type of big-game hunting. Whether it’s black bears over bait or glassing for brown bears, a spring bear hunt will help ward off the irritability and shortness of breath that is usually experienced when one realizes how far off deer season actually is.
3. It’s not just about the bears.
Many of the areas in which spring bear hunts are conducted also offer great fishing. Where I hunted in Quebec, the early morning was usually spent checking the bait stations, and a good part of the day—up until about 3:00 p.m.—was spent fishing the numerous lakes. Fresh fish, neatly fried up, was a delicious treat in bear camp, and with a minimal amount of fishing gear, we had a great time. Depending on the area you’re hunting, deep sea fishing may be involved, or perhaps fly-fishing for trout in a Western stream, but no matter, you’ll be outdoors all day long.
4. Bear hunting is an amazing experience.
Be careful, you may end up with a new favorite hobby. Bear hunting can be addictive, as they are after all dangerous game. Even a black bear can turn the tides on a hunter, especially if hit wrong, so hunting them requires a bit of a different level of attention than other animals. They’re smart, wary and silent. They can be brazen—I’m sure you’ve seen videos of a bear climbing the very tree that a hunter occupies—and they can be as witty as they come, circling the bait station, just out of range, until they feel comfortable coming in. Sometimes they’ll wait until well after dark, especially the big boars that have been educated, and though you’ll find tracks, you’ll never get a glimpse of him. Only when you’ve seen a bear will you get an idea of exactly how quietly they walk on those large pads, adding to the mystique. If it’s a brown bear you’re after, well, that alone is an amazing experience, and one I’m keen to have. It’s beautiful, rugged country and just being there is worth the price of admission.
5. It just might be an excuse to buy a new rifle.
Well, not that any of us really need an excuse to buy a new rifle—I’m a firm believer in ‘the-more-the-merrier’—but this is as good a justification as any. Been wanting that .35 Whelen? Perhaps that sweet .300 Magnum you’ve been eyeing is just an excuse away from joining the team. No matter, so long as it’s a bear-worthy caliber—usually .270 and up for the black bears, and .300 on up to around .375 for the browns—I say go ahead and set up your own bear rifle. Maybe a rugged, all-weather affair makes sense for the locale you plan to hunt, or it may just be a familiar design in a different caliber. You could also experiment with a different projectile in a rifle you already have, something good and strong that can easily break those large shoulder bones. At any rate, the planning and purchasing of gear can be an awful lot of fun, and booking a bear hunt is a good impetus for just that.
I wish more states would open up a spring season for bears. Populations are most definitely on the rise, and the additional license money would help keep our public lands well-funded. There are some very affordable bear hunts available. I know I’ve seen some good deals for black bear in Idaho, Quebec and Alberta, and some very expensive ones as well—an Alaskan Kodiak bear hunt is no small financial investment—so there should be something for almost everyone’s budget. Get on the computer, make some phone calls and start planning your great adventure.