Bore Sight Question

[one eye joe]

Are you turning the adjustment the correct way? If the cross hairs are high, you should be turning the adjustment in the "up" direction. I know it sounds counter intuitive, but this is how a scope works when trying to line up a laser bore sight.

When making adjustments with a scope you're moving the point of impact, not the reticle. Think of it as though you're trying to move the laser, not the reticle.

DESPITE THIS BEING COUNTERINTUITIVE, THIS MAY SOLVE YOUR PROBLEM.....

IMHO---I SERIOUSLY DOUBT THAT YOUR LASER'S ALIGNMENT, OR LACK THEREOF, IS THE PROBLEM....

OF COURSE I COULD BE WRONG. THAT'S EXACTLY WHY I PREFACED MY REMARK WTH, IMHO......

 

[Rastoff]

DESPITE THIS BEING COUNTERINTUITIVE, THIS MAY SOLVE YOUR PROBLEM.....

IMHO---I SERIOUSLY DOUBT THAT YOUR LASER'S ALIGNMENT, OR LACK THEREOF, IS THE PROBLEM....

OF COURSE I COULD BE WRONG. THAT'S EXACTLY WHY I PREFACED MY REMARK WTH, IMHO......

See post #4.

 

[tozan]

Mounted a Leupold Rifleman 3-9X40 scope on my Sport using Leupold riser mounts. When I tried to bore sight using a laser cartridge I cannot move the POI up far enough to line up the laser and the cross hairs. I was using a distance of about 50 yards. What am I doing wrong? Is the mount too tall? It measures 1" from the rail to the bottom of the scope tube.

The center of bore to center of scope is most likely around 2 inches. At 50 yards it will take a lot of adjustment to get to a zero.

So for a quick bore sight I would come back to 25 yards tops.
Aim the laser to be about 30 mm below the cross hairs point of aim.

This should easily get you on paper so you can finishing the zero at the range.

 

[jake1945]

"Old School" method is best. It's what I've done for decades. I align the bore on an object at approx. 50 yards then adjust the scope to that object. Simple! Laser sighters are really inaccurate.

 

[steelslaver]

I agree with and use the old school bore alignment method.
I got a couple new rifles and 3 new scopes, then I played mix and match with a total of 6 rifles. Once I had the scopes mounted, I set each rifle on a rest setup with bolts out, (you could do same with just an upper as mentioned above). Then using a mark about 50 yds away, I centered mark looking down bore, then dialed the scope to the mark. Took them to the range. Each fired high at 100yds, and within a couple inches side to side, but it was easy to finish dialing them in. I didn't try to get them dead on the mark. Just wanted to hit the paper at 100 yds. because there is no way to trust anything but actual firing.

Most calibers I set about 3" high at 100yds and am then close at 200yds and a bit low at 300yds. Know where your rifle strikes at a given yardage then know your ballistic table, then its all range estimation, wind doping.

 

[Rastoff]

The center of bore to center of scope is most likely around 2 inches. At 50 yards it will take a lot of adjustment to get to a zero.

I'm surprised to keep hearing this on an AR forum. Zeroing at 50 yards is very common in the AR world.

The normal scope height (height over bore) for an AR is 2.75". This means that if they're both parallel, the bullet will impact ~2.75" (bullet drop is negligible at this distance) high at 50 yards. That's only 5.5MOA. For most scopes that's only 10-11 clicks, he has 28 available from the middle point. So, not really that much adjustment.

 

[jimbo728]

The center of bore to center of scope is most likely around 2 inches. At 50 yards it will take a lot of adjustment to get to a zero.

So for a quick bore sight I would come back to 25 yards tops.
Aim the laser to be about 30 mm below the cross hairs point of aim.

This should easily get you on paper so you can finishing the zero at the range.

Took me 9 shots. 3 clicks up and 3 clicks left to zero at 50yds after bore sighting. For 100 yds Had to go down 6" for the 100 yd zero that I settled on.
It`s not rocket science.
Jim

 

[bamashooter]

I'm surprised to keep hearing this on an AR forum. Zeroing at 50 yards is very common in the AR world.

The normal scope height (height over bore) for an AR is 2.75". This means that if they're both parallel, the bullet will impact ~2.75" (bullet drop is negligible at this distance) high at 50 yards. That's only 5.5MOA. For most scopes that's only 10-11 clicks, he has 28 available from the middle point. So, not really that much adjustment.

Same here. The info you quoted is wrong in my too long to care experiences. All of mine are 2.50 / 2.75. I zero at 50 meters and it's about as easy as it gets.

EDIT: Red dots / hard sights at 50 meters. Variable scopes at 100 meters.

 

[C J]

"Old School" method is best. It's what I've done for decades. I align the bore on an object at approx. 50 yards then adjust the scope to that object. Simple! Laser sighters are really inaccurate.

Using a laser is never anything except a starting point. Especially if you have a powerful scope just getting close to zero can be a problem. I use a laser to get my scopes close and then use the traditional method to zero after that. I've never seen any scope that was truly zeroed from just using a bore laser. Distance, power of the particular bullet you're using, and other factors come into play. The "only" way to get a scope zeroed is to use the old fashioned method if you want to shoot accurate.

 

[Rastoff]

The "only" way to get a scope zeroed is to use the old fashioned method if you want to shoot accurate.

Everyone agrees that only by actually shooting can you get a scope zeroed. What jake1945 meant by the "old school" method was how the bore sighting was done. This was by looking through the barrel.

The laser does the same thing, but I too prefer the look-through-the-bore method.

 

[tozan]

I'm surprised to keep hearing this on an AR forum. Zeroing at 50 yards is very common in the AR world.

The normal scope height (height over bore) for an AR is 2.75". This means that if they're both parallel, the bullet will impact ~2.75" (bullet drop is negligible at this distance) high at 50 yards. That's only 5.5MOA. For most scopes that's only 10-11 clicks, he has 28 available from the middle point. So, not really that much adjustment.

I guess most of you missed the part according to the OP's post he is attempting to BORE sight with a laser at 50 yards not shooting at 50 yards. Big difference It would certainly be much easier to see a laser dot and adjust to it at 25 or even closer maybe even 20 t0 30 feet I prefer to do it inside my house... If his laser is way out of calibration the farther out you get the farther off it will be plus at 50 yards a lot of the laser bore sighters can not even be seen...

Once on the spot take it to the range and shoot and adjust. Like you said it is not rocket science... If you and the firearms are up to the task it should only take 3 rounds to verify at 50... I would then fine tune it at 100 or 200 or whatever you want your final zero to be...

 

[Mike1647]

Update-10/20

Distance was the problem, not the scope or mount. Was able to get out today and bore sight then fire a few rounds before it rained a bit. I'm not through yet but I am "on paper" with no problem at about 100 yards give or take a few yards. Now to make a rifle rest to finish the zero process.
PS-the Sport performed flawlessly, no problems at all so far. I really like this rifle.

 

[bamashooter]

Good deal. Once you get it "mechanically" zeroed", test and tweak it in the actual environment you expect to use it most of the time, for example, standing, prone, kneeling, etc.

 

[C J]

If his laser is way out of calibration the farther out you get the farther off it will be plus at 50 yards a lot of the laser bore sighters can not even be seen...

A bore sight can not possibly be "out of calibration". It shines down the bore. It can't do anything else. If it doesn't align with the bore it does not make a dot, it makes a pattern. The thing the OP has to do is figure out where he really wants the sight to aim. The bore sight only tells you what is straight out from the bore. You have to compensate for the rise and fall of bullets as they come out of the bore (depending on the distance involved) relative to the line of sight of the red dot. If you set a red dot on the laser dot at 100 yards you will almost certainly hit above where your sight is pointed. Lasers are capable of shining a very long distance in low light. That's the time to use a bore laser.

Again a bore laser only gets you close. Once you get close you have to walk the sight in based on exactly where your POI is. There is no shortcut that eliminates that step.