Rifle Scopes Q? tips on laser bore sighting a new scope?

[super jim]

New to .308 and new to scopes:

Gun: DPMS LR.308B, A2 flat top. Scope Bushnell 4-12x40, Multi-X reticle.

intended use: Target & plinking. 50 yards to 300 yards...maybe a little more someday.

Using internal bore laser to sight the scope.

Question: Should I zero the scope to the laser dot at +/- 0" at 25 yards?
Or at +/-?" at 100 yards?
or something else.

Specific ammo yet to be determined but will likely vary.
Just need a starting point.

Also, I assume with this scope reticle, hold-over is best for adjusting for range? Not the elevation adjustment on scope, correct?

Thanks for your help.

 

[RobertB]

Re: Q? tips on laser bore sighting a new scope?

I don't use bore sights but I would guess just get the reticle on the dot at say 10 yds or so then it should be on paper at 100 yds. Just put up a bigger target if not. Be carefull not to damage your barrel crown if its the kind that goes on the muzzle. Sounds like you have the kind you put in the chamber. Then look at your scope, it most likly will say 1 click=1/4" at 100yds or 1 click=1/8th inch @100yds. You can adjust elevation either way. Find out which one you aroek better with. Good luck

 

[super jim]

Re: Q? tips on laser bore sighting a new scope?

Does this look correct?
My distance from scope line of aim (LOA)to point of aim (bore) is 2.5".

Looking at .308 trajectory charts, it appears that to have the scope zeroed at 200 yards, the point of impact(POI)would be approx. 1.5" above the LOA for the scope at 100 yrds.

And at 50 yards, the POI would be approx. +.25"
And at 25 yards, the POI would be approx. -.75"
Look right so far?

Then, where would should the Scope LOA be in refference to the bore sight laser dot at 25 yards and 50 yards and 100 yards?

The laser beam does not have a trajectory, so the difference will not be the same, and the difference will increase with distance.

I have not be able to find this information.

So in summary, my question is: at 25 and/or 50 yards, what should I set the distance between the cross hairs and the laser dot in order to have the scope zero at 200 yards?

 

[patriotoutlaw]

Re: Q? tips on laser bore sighting a new scope?

You may have to start at closer distances with the laser. If it came with directions, it should tell you the optimimum distance to set your target. You can also remove your upper or break it over, remove bolt carrier assy., put your upper in a gun vice and line up your bore with a target on the farside of your shop, basement, living room and adjust your crosshairs accordingly, w/o a bore sight. With your duplex reticle you can use the crosshair graduations as aiming points, as long as you know the target distance and power setting on your scope. If your scope "shoots the box" and has audible clicks you can move your POI just like with target knobs, just not as easily/quickly. Also, don't forget the number of clicks. Although, this CAN be done, Kentucky windage is the rule of thumb with these turrets and reticles.

 

[Redmanss]

Re: Q? tips on laser bore sighting a new scope?

Typhoon, you're reading too much into it in my opinion. Just use the laser to match up the point of aim about ~1" above the dot from the laser at <25yds, or right on at a further distance. This will put you pretty close to being on when zeroing at 100yds or wherever. A bore sight is to get you on paper saving ammo, not to replace zeroing entirely.

Honestly, I never use lasers to bore sight anymore. I remove the bolt/bolt carrier and look down the barrel. Line up the bore and the reticle or whatever other aiming reference I'm using with something identifiable at a distance, and I'm always on paper at 100yds. Last time I did this with my MK12 I was 2" off of POA at 100yds, so it is plenty accurate enough.

 

[RandyD]

Re: Q? tips on laser bore sighting a new scope?

When installing a scope it is easier for me to manually line up the scope with bore, then fire at least one round at 25 yards, make a correction then go out to 100 yards.

I once used a lazerbore sighter and then wasted an entire box of ammo trying go get on paper at 100 yards. That experience left me with the opinion that lazer boresighters are gimmicks.

 

[netranger6]

Re: Q? tips on laser bore sighting a new scope?

+1 on manual bore sighting. Lasers and other types have never worked for me. Here's what you do:

Take apart upper/lower receiver. Remove bolt from upper. Place upper on something solid. Look through the bore at something 100 yards away, or your preferred zero distance. Find a square, usually the target, but I use my neighbors garage. Move your upper until you have the intersection of Top left, top right, etc.., centered in your bore. Keep it steady, and move your reticle to that point. re-assembe, fire and adjust.

 

[super jim]

Re: Q? tips on laser bore sighting a new scope?

Thanks everyone. Probably the mechanical engineering backgroud in my just complicating things. I'll give it a try in a couple hours.

 

[CMH]

Re: Q? tips on laser bore sighting a new scope?

When I first read the title of your thread I was trying to figure what the hell Q-tips had to do with bore sighting.

 

[MEDICGORDO]

Re: Q? tips on laser bore sighting a new scope?

Just take the bolt out look through the bore and adjust the scope.whatever you do no mater how stupid this sounds don't forget to remove it before you drop the hammer on a round!!

 

[Buddhapapa]

Re: Q? tips on laser bore sighting a new scope?

I laser bore sight my semi-automatic rifles because I cannot remove the bolts easily to look through the bore. I first do it at home at the boresighter manufacturer's recommended distance and then at the range sight the rifle in at 50 yds. This always gets my first shot on the paper at 100 yds and then sight as usual. Always gets me sighted in in less than a box of ammo.