Scope sighting

[Mark75H]

My collimator may not be perfect, but its better than my eye.

Can you clarify the use of the level? Where on the rifle is the level placed? the scope rail or across some part of the receiver that is truly horizontal? Will this only work on a scope with some kind of flat surface on the top - or am I not understanding where the level is placed on the scope (some of my cheap scopes don't have any flat surface that I am certain is true to the crosshairs)? Are the turret caps sufficiently accurate?

I am certain your rifles and scopes are both better than mine ... and I rarely even attempt 200 yards with my Marlin 60. I'm happy just to hit the paper or target stand at that distance, but I'm improving.

 

[E.Shell]

My collimator may not be perfect, but its better than my eye...

Just a question, not critisizm. There are always different ways to do things.

...Can you clarify the use of the level?...

Yes.

...Where on the rifle is the level placed? the scope rail or across some part of the receiver that is truly horizontal?...

I normally use the rail, unless the rifle action has a horizontal feature that can be accessed. Some models have a flat tang, others an integral rail. If it's a bolt-on rail, the screw holes may not be perfectly aligned with the action centerline, but an average can be taken. With a radius receiver bridge & ring, one can only get as close as factory tolerances without setting the action up on a lathe and finding the top centerline, based on the action screw centerline - theoretically on opposite sides of the cylinder.

Once the action is leveled, the scope can be addressed.

...Will this only work on a scope with some kind of flat surface on the top - or am I not understanding where the level is placed on the scope (some of my cheap scopes don't have any flat surface that I am certain is true to the crosshairs)?...

Yes and no.

If the scope has a horizontal reference, the level can be used.

If the scope has no horizontal reference, a plumb bob string can be tracked with the vertical adjustments to ensure the crosshair intersection follows the string.

...Are the turret caps sufficiently accurate?...

If they are sheet metal, no. If they are machined, probably. It is difficult to cut a piece of material off or finish the end surface asymetrically while it's spinning on it's axis in a lather or screw machine. They can be checked by leveling side to side, the spinning the turret 90 degrees and rechecking, then 180 degrees and rechecking. If the cap is not square to it's axis, the level will show us.

The turret itself is generally perpendicular to reticle travel, and almost has to be when one considers it's actual function. A turret merely surves as a jack screw, and the threads draw the reticle back and forth within the tube. Even if the reticle features themselves are not square with the screw axis, the intersection will still move on the same plane.

 

[Tactics]

Wow. Thanks for the great post! Tons of info here and I just got a new set of optics. Thanks E. Shell.

 

[BenL]

It always takes me forever to level a scope. Even with a set of scope levels, it's a pain. It will look level until I tighten it down, then will be unlevel again.

I have never mounted a scope that was level on the first attempt.

 

[axshon]

It always takes me forever to level a scope. Even with a set of scope levels, it's a pain. It will look level until I tighten it down, then will be unlevel again.

I have never mounted a scope that was level on the first attempt.

Ok, judging from some of the groups you've posted I'm REALLY happy to hear that! Makes me feel like I wasn't wasting my time spending 90 minutes on the deck adjusting the damn scope.

 

[IndispensableDestiny]

Incorrect. The target (on earth) will move out from under the bullet if time of flight is long enough.

I was referring to a bullet fired vertically. Both the target and the bullet are in the same frame of reference. Both are moving at the same angular velocity. The lateral range is zero.

Parallax or eye relief?

Both. The heavy coat is keeping the rifle further out from my eye and away from my strong (shooting) side.

 

[Mark75H]

Thanks again, Ed. You answered all my questions and explained stuff I didn't know I didn't know

 

[Celtic159]

I picked up my first AR yesterday (Colt 6920 Magpul) and need to zero the sights (as well as the Aimpoint. I've never zeroed an AR before, and I'm unclear as to how I approach this given that the BUIS is windage-adjustable only. I plan on a 50/200 zero, but would appreciate any help/pointers out there.

Thanks in advance.

 

[Half-cocked]

I picked up my first AR yesterday (Colt 6920 Magpul) and need to zero the sights (as well as the Aimpoint. I've never zeroed an AR before, and I'm unclear as to how I approach this given that the BUIS is windage-adjustable only. I plan on a 50/200 zero, but would appreciate any help/pointers out there.

Thanks in advance.

Elevation is adjusted using the front sight. You'll need a special tool to raise/lower the post.

If you don't have the tool, yet, you can just zero you Aimpoint for now and leave the iron sights for later.

 

[wilcam47]

I picked up my first AR yesterday (Colt 6920 Magpul) and need to zero the sights (as well as the Aimpoint. I've never zeroed an AR before, and I'm unclear as to how I approach this given that the BUIS is windage-adjustable only. I plan on a 50/200 zero, but would appreciate any help/pointers out there.

Thanks in advance.

Start at 25yds with reactive targets...as for the other I dont have experience with

 

[huesmann]

The front sight tool is about $10-12 at your FLGS.

 

[cobra]

I use a large 4' piece of plywood or card board as a back stop to my target when starting from scratch sighting in new scope.
50 yards away with targets that have 1" lines on them.
This makes finding your first shots easyer due to the large back stop.
Having the graduated lines on target makes it easyer to walk in your adjustments.
Just remember if scopes turrets are marked for example 1/4" per click at 100 yards.
1 click will be 1/2" when sighting in at 50 yards.
A bore sight helps if avalible