How do I sight in a laser on a AR-15?

[BSA1]

How do I sight in a laser on a AR-15?

The gun is 5.56 with 16” barrel and quad rail and pop up Magpul front and rear sights.

I have mounted a Crimson Trace CMR-201 Rail Master Red Laser Sight on the front of the bottom rail. Shouldering the gun to dry fire it the red dot prints on the wall several inches lower than my point of aim using the iron sights.

I am going to an outdoor shooting range this week with the gun. How do I sight in the laser and iron sights to the same point of impact? I will be using 55 gr. FMJ PMC Bronze as control ammunition.

Do I adjust the iron sights to the laser p-o-i or the other way around?

At what distance? Closest distance on rifle range is 25 yards but I have a portable frame to set up a target closer.

Do I need to move the laser sight from the bottom rail to a side one? I prefer the bottom rail position as it is easier to switch off and on along with gripping the gun.

Just learn to live with the different p-o-i's?

edited to remove off-topic drift.

 

[Laphroaig]

I understand the laser is projecting a straight beam of light whereas the iron sights are compensating for bullet arc.

I don't agree with that statement. Both systems rely on a straight line from the rifle to the target that will intersect the bullets trajectory at two distances.

Assuming your iron sight picture is center of mass, I'd sight the irons to be 1" low at 25 yds. Check at longer distances but you should be on (or close) at 50 and 200 yds, and approx. 2" high at 100. I'd then adjust the dot so that I'm on at 25.

 

[ColoradoMinuteMan]

I agree with Laphroaig, a laser sight is no different from an iron sight from the perspective that they both draw a straight line, that then intersects with the arc of the trajectory of the bullet in 2 places. You sight it in similar to iron sights, or a scope, in that you determine the distance you want for zero, then you align the sites to the point of impact at your chosen zero distance. If you have multiple sights you have to either align them at the same chosen zero distance, or accept that they will not be aligned. Often I've seen where people use different sights for quickly changing between zero distances. Because, each site is not perfectly centered to the bore, they will always be off slightly.

 

[Dr T]

As for the mechanics. I assume that the the gun is sighted in with irons the way you like it.

I would get a laser bore sight similar to this (https://www.midwayusa.com/product/2738211655/sightmark-laser-bore-sight) and superimpose the dot from your laser sight on the dot from the bore sight at a convenient distance. Then move to a target at your desired range and fine tune it. It helps if it is dark

 

[CapnMac]

The practical answer is that you need to put some holes down range. How many is a different debate--me, I like 10. You use that center and bring the irons, and the laser to that point..

Please note I am making no presumption that the irons will shoot to POI, I've yet to find a rifle which did that.

So, adjust your "aiming" tools so that they impinge on where you shoot the arm to POI. At which point, those tools POA ought to be POI.

 

[BSA1]

The practical answer is that you need to put some holes down range. How many is a different debate--me, I like 10. You use that center and bring the irons, and the laser to that point..

Please note I am making no presumption that the irons will shoot to POI, I've yet to find a rifle which did that.

So, adjust your "aiming" tools so that they impinge on where you shoot the arm to POI. At which point, those tools POA ought to be POI.

I have not shot this gun much. I think only one time (last Fall) which was at 25 yards using a wobbling rest and chair that was too low. It was a function test to make sure I assembled everything correctly. However as I recall it shot pretty close to p.o.i.

So are you saying first adjust the iron sights to where I want my groups. (Irons are my primary.) THEN adjust the laser to that same p.o.i.

Where should my groups be at 25 yards for 100 yard zero?

PMC Bronze shows -1.5" at 25 yards, +2.0" at 100 and 0.0 at 200 with 55 gr. FMJ at 2900 fps. (Actually this is pretty practical for my use).

 

[Bfh_auto]

So are you saying first adjust the iron sights to where I want my groups. (Irons are my primary.) THEN adjust the laser to that same p.o.i.

Where should my groups be at 25 yards for 100 yard zero?

PMC Bronze shows -1.5" at 25 yards, +2.0" at 100 and 0.0 at 200 with 55 gr. FMJ at 2900 fps. (Actually this is pretty practical for my use).

What you just wrote is pretty much what should be done.
Sight primary 1.5 low at 25, then set laser to dead on at 25.
Do this by aiming your irons at the bull and adjust the laser to point 1.5 low. When you get close test fire. This will save a little time.

 

[BSA1]

Thank you for your help.

 

[gillmeister692]

Bore sight it. Remove the BCG (bolt carrier group); look down bore at desired point-of-impact; compare with laser dot; adjust laser windage & elevation knobs to coincide with view through bore. You're now on paper.

 

[imashooter]

I have several lasers and here's how I do it. I prefer 25 (meters). All of mine are mounted below and near muzzle end of handguard. You might need low-light conditions or shade on your target.

Aim at "bullseye" and fire weapon.

If the impact is 2" to the right, adjust beam until the beam is covering the impact while you are still aiming at your original point of aim. Same deal with the vertical. No need to try and make the adjusments while trying to steady the weapon down range. Just remove it from your firing position and make the changes. Now assume your firing position remembering you original point of aim and see where the beam falls. Normally takes 2-3-4 attempts to nail it.

If you choose to zero at 25, keep in mind the poi will be a little high on targets which are closer to you. You'll quickly learn how to adjust your poa for close in targets or even for some farther out. Lasers are typically adjusted in very small increments, especially at 25 meters / yards.

 

[z7]

I would want the laser to be sighted in at 25yds or less, irons 50 or 100yds

I imagine a laser being handy inside a dark House

I would not try to make the point of impact the same with a laser and irons, sight them differently to meet your goals, you can’t shoot the laser at 200yds (or I could not)

 

[BSA1]

I have several lasers and here's how I do it. I prefer 25 (meters). All of mine are mounted below and near muzzle end of handguard. You might need low-light conditions or shade on your target.

I just got back from the range. It was generally unsatisfactory as far as the laser sighting-in.

The good part is I adjusted the iron sights from shooting 2" high to 1 1/2" low at 25 yards.

As for the laser I could not see it past 6 yards. Weather is bright sunshine and 80 degrees. At 6 yards the p.o.i. is exactly where the red dot is at. Nice but at 6 yards I am most likely going to point shoot without using sights or laser. I definitely need low light conditions to see the laser beam farther out. The beam is very bright sighting across my dim basement.

So for the moment I am done with the laser sight. The windage is perfect. Just going to wait for a dark, cloudy day to test it some more.

 

[JeffG]

My problem(s) with laser sights is as follows:
1. From where the laser dot can be seen by me, I don't need it to guide my shot.
2. If I am shining a light source, I can be located.
3. The laser is usually emitting from a different location on the weapon; giving a different line of sight (angle) from the irons or the scope.
4. If the laser encourages the firearm to be shot from an ill-mounted stance, the firearm will recoil differently, and the shot will land in an unintended POI.

 

[The Earl o Sammich]

Lasers are a short range, fast acquisition sight. Clamp your upper in a vice and with BCG removed sight through the barrel at a dot on the wall from across the room. If you can "aim through the bore" accurately enough you will be dang close. With the upper snug, adjsut your laser to the same point but an inch and a half higher to take into account the difference over barrel bore. You will be on paper at fifty yards.

 

[imashooter]

I just got back from the range. It was generally unsatisfactory as far as the laser sighting-in.

The good part is I adjusted the iron sights from shooting 2" high to 1 1/2" low at 25 yards.

As for the laser I could not see it past 6 yards. Weather is bright sunshine and 80 degrees. At 6 yards the p.o.i. is exactly where the red dot is at. Nice but at 6 yards I am most likely going to point shoot without using sights or laser. I definitely need low light conditions to see the laser beam farther out. The beam is very bright sighting across my dim basement.

So for the moment I am done with the laser sight. The windage is perfect. Just going to wait for a dark, cloudy day to test it some more.

Visible lasers have little to no utility in bright daylight.
I would never engage an armed person with a visible laser without either a remote or switch within quick reach of either hand.
There is no sensible correlation between a laser and hard sights or optics. Sure, at some point in space the trajectory of a bullet may cross where a red dot, hard sight, etc and the beam intersect.

Regarding an "ill - mounted stance", sometimes that's well advised as it's the only option. For example, night time, the friendly takes cover behind a tree to avoid being hit. Engage the laser, swing weapon around tree, take a quick peak and fire. Most of the body remains shielded for that moment. Your down and can no longer bring sights to eyes. Just put the dot on the target and hope for the best. Without the laser you're sure enough dead. With the laser you have a chance. Lasers indeed have utility if you know how to take advantage of them.

Another example is at night inside of home. Laser or not, you must see the target. With a laser, you don't need to waste time shouldering the weapon, fixing the target with hard sights or optics, engage target. Simply lase the target and be done with it.

 

[CapnMac]

So are you saying first adjust the iron sights to where I want my groups. (Irons are my primary.) THEN adjust the laser to that same p.o.i.

Close.
Each of us shoulders up a rifle a bit differently.
So, shoot a group. Regulate the irons to match that group, mostly left to right. Decide on what "zero" you want (100, 200, 225, etc) and regulate the sights to achieve that.
With that in hand, bring the laser to that point that uits best.

Now, you'll need a heavily overcast day if shooting outdoors, or possibly an indor range.

The above on range and light limitations of lasers does apply.

 

[SharpDog]

If you have a sighted-in sight or optic system, adjust your laser so its image is where you want it in your optic pattern. The laser is linear, just like your sights, so no mystery there.

 

[shoobe01]

I don't use viz lasers, but have several IR laser equipped guns. While they do mostly do their work at close range, I reduce brainpower by having all sights on a weapon work the exact same way. RDS, BUIS, Laser. All zeroed the same way to hit at the same place.

Now, the laser is in a different plane than the other sights, so how does that work? Offset. Just like the RDS/BUIS is higher than the bore (by a lot on an AR15), I zero the laser for the relative offset. My 5.56 carbines are 25/200 zeroed, so I zero the laser to be (in my case, where you mount yours will vary) a bit lower and left of the day aiming point (I measure when doing it, not just fudge the "a little bit") .

Critically: I am only a good enough shot to tell that difference while zeroing. The rest of the time, it all comes out in the wash, and simply aiming dead on, and firing, works fine. I can do headshots at 10 yds or hit the 8" plate (the 4" is hard!) at 300.

 

[boom boom]

Red lasers are pretty much a short distance proposition, especially in daylight. You might try green lasers for a bit longer range which depending on the background are a bit more energetic (but drain batteries faster and are more expensive generally). As you move up the Roygbiv scale, red is the least energetic light and violet the most. Green is in the middle.

 

[BSA1]

Lasers are a short range, fast acquisition sight. Clamp your upper in a vice and with BCG removed sight through the barrel at a dot on the wall from across the room. If you can "aim through the bore" accurately enough you will be dang close. With the upper snug, adjsut your laser to the same point but an inch and a half higher to take into account the difference over barrel bore. You will be on paper at fifty yards.

The bullet impacts exactly where the laser dot is showing at approximately 6 yards so it is reasonably bore sighted.

Now, you'll need a heavily overcast day if shooting outdoors, or possibly an indoor range.

This is my problem with the laser. The dot washes out for me beyond 6 -7 yards in bright sunlight. I doubt if a cloudy day will help any. I am not sure if any of the indoor ranges allow shooting a AR with FMJ.

In general I am totally unimpressed with the laser sight on a long gun. The good news is it was free so I am not out any money otherwise I would upset with myself for spending $160.00 on it.

All is not lost. I live in the country so I can build a backstop and sight it in late in the evening. (For the record FMJ penetrates through 2 milk jugs and is trapped in the 3rd one. It is a interesting looking bent bullet). The only possible practical use I may have for it is ambushing a predator that is raiding the chicken coop early in the morning but a shotgun may be easier to use.

 

[imashooter]

Site it in however you need to but don't expect to use it or a green laser in daylight at any distance beyond 10 meters. Doubtful if the red would go that far effectively. And when you zero, smooth-surfaced, light colored targets are better as they reflect light opposed to dark colors which absorb light. I have 2 good quality green lasers that are very usable in daylight out to 10 meters. They're pretty much gone nearing 20 meters unless you "search" for the dot which does no good for its intended purpose. Good luck with it.

 

[Dr T]

The red laser at night on a white shirt is great for the movies, but I wonder about the utility on a rifle for any but close range work.

As for visibility, I put this little guy on my Mossberg Shockwave ($45 from Amazon--the laser, not the Shockwave):
Ade Advanced Optics HG54G Strobe Laser Sight for Pistol Handgun, Green

I have been much more impressed by the visibility of this green dot than I have by the red dot Crimson Trace's I have on various handguns. It seems bright enough to be a weapon in its own right (And an impressive customer warning about shining anywhere except the target).

I sighted it in on the Shockwave using the method I described above. Given my expected use for this "other firearm", It should be more than adequate for helping me target rattlesnakes of the zero- and two-legged varieties easily. In the case of the two-legged, it may be intimidating enough in its own right to achieve the desired result.

 

[Bfh_auto]

The bullet impacts exactly where the laser dot is showing at approximately 6 yards so it is reasonably bore sighted.



This is my problem with the laser. The dot washes out for me beyond 6 -7 yards in bright sunlight. I doubt if a cloudy day will help any. I am not sure if any of the indoor ranges allow shooting a AR with FMJ.

In general I am totally unimpressed with the laser sight on a long gun. The good news is it was free so I am not out any money otherwise I would upset with myself for spending $160.00 on it.

All is not lost. I live in the country so I can build a backstop and sight it in late in the evening. (For the record FMJ penetrates through 2 milk jugs and is trapped in the 3rd one. It is a interesting looking bent bullet). The only possible practical use I may have for it is ambushing a predator that is raiding the chicken coop early in the morning but a shotgun may be easier to use.

If you have armadillos, it works great for hunting them at night. Nothing like chasing armadillos in the cow pasture.