[Lead Slanger]

The other day I was getting a measurement for a scope ring lapping bar I was going to make when my boss told me that getting my scope perfectly level with my reciever was what I really needed to be worried about. He's not the first person that has told me that either. I'm still trying to figure out why that is so crucial? Here's the way I have it figured in my head.....

If the point of impact is the same on a level or an unlevel scope (center of crosshairs), wouldn't the crosshairs being unlevel only affect the adjustment? (If leaning right, an adjustment up would actually be up and to the right) Is there something I'm missing or is adjustment the only thing affected by the scope being unlevel?

 

[Spike12]

The issue becomes serious when you use the cross hairs for hold over or windage.

If the scope isn't level when you use hold over, for example, your point of impact will not move truly vertical, but rather off to one side.

 

[North country gal]

If the point of impact is the same on a level or an unlevel scope (center of crosshairs), wouldn't the crosshairs being unlevel only affect the adjustment? (If leaning right, an adjustment up would actually be up and to the right) Is there something I'm missing or is adjustment the only thing affected by the scope being unlevel?

Yes. the adjustment is affected, but it can make getting sighted in brutal in the case of being way off of level. A little off is not a big deal if you only plan to sight in once and forget it, but even a little off can make things unnecessarily difficult if you are changing adjustments on a regular basis. It is relatively easy to level the scope, so why not just do it right the first time?

 

[Hairtrigger]

I hope you did not stop progress on the lapping bar!
I will not put a quality scope in unlapped rings.

 

[terry_p]

To me a level scope tells me I'm not canting my rifle when I sight on whatever I'm shooting at. It would be distracting when I'm ready to shoot an animal. I want to be focused on sight picture and "squeeze" as that is plenty to worry about when the adrenaline is flowing. I use my bore sighter to get it level and that has served me well. Is it perfect no but it is as close as my old eyes will get it.

 

[Lead Slanger]

The issue becomes serious when you use the cross hairs for hold over or windage.

If the scope isn't level when you use hold over, for example, your point of impact will not move truly vertical, but rather off to one side.

I can see that. That makes sense.

 

[Lead Slanger]

I hope you did not stop progress on the lapping bar!
I will not put a quality scope in unlapped rings.

Oh no....the lapping bar is more important to me than the scope being level. He goes through great lengths to makes sure his scope is level, but doesn't lap his rings. Go figure.

 

[Lead Slanger]

To me a level scope tells me I'm not canting my rifle when I sight on whatever I'm shooting at. It would be distracting when I'm ready to shoot an animal. I want to be focused on sight picture and "squeeze" as that is plenty to worry about when the adrenaline is flowing. I use my bore sighter to get it level and that has served me well. Is it perfect no but it is as close as my old eyes will get it.

That's the truth.

 

[Dozer02]

Cabelas sells an inexpensive "bubble" leveling system that will get your crosshairs or recticle perfectly level with your reciever. It's worth the couple bucks if you have several scoped rifles. I "eyeball" mounted a new Leoupold on my latest Savage rifle purchase just to see how much off it'd be, I then used the leveling bubbles to zero it and sure enough I was way off! It looked good by eye but the bubbles don't lie! (lol)

 

[ZommyGun]

The other day I was getting a measurement for a scope ring lapping bar I was going to make when my boss told me that getting my scope perfectly level with my reciever was what I really needed to be worried about. He's not the first person that has told me that either. I'm still trying to figure out why that is so crucial? Here's the way I have it figured in my head.....

If the point of impact is the same on a level or an unlevel scope (center of crosshairs), wouldn't the crosshairs being unlevel only affect the adjustment? (If leaning right, an adjustment up would actually be up and to the right) Is there something I'm missing or is adjustment the only thing affected by the scope being unlevel?

I am not an expert but I would think that the range of elevation adjustment of the scope, the type and caliber of the gun, and the range you need to use it at matter the most...also scope objective size factors in due to to height of scope...

Lots of people with 22s wind up needing elevation added to the rings/rail to get the nominal distance centered in the adjustment range and still be able to get long range sight adjustment...

I lapped added elevation into rings I converted from tip off rail mount to being bolted directly to the receiver on the 1022

IMO...you should try to lap your rings trying your best to get the cross hairs on target at your nominal distance with the cross hairs adjusted to mid point on both windage and elevation...

Check out Ryan Cleckner on youtube...master sniper school instructor has lots of videos on scopes and how and why you should do whatever...

The last thing you want to do IMO is have the windage off center and/or the scope objective higher off the receiver then the eye piece...

Level of pointed down very slightly to increase elevation range is better...and you should consider scope eye level (center of scope tube) relative to the center of the bore when making any decisions...

Check out Ryan Cleckner on youtube...master sniper school instructor has lots of videos on scopes and how and why you should do whatever...

I set my vertical cross hair to be perpendicular/plumb when holding the rifle in the most comfortable and secure position for off hand shooting...which means when the gun is perfectly straight up/down in a vise the scope vertical cross hair is slightly canted...

If you use the Ryan Cleckner methods including and especially the cheek rest you find that it is very difficult to hold the rifle securely and NOT have the cross hairs be plumb/level...you will not have to move/shuffle/adjust/compensate to get the right hold to be consistently plumb/level...when the combination of scope canting and cheek rest is dialed in it is hard to not be right on...

 

[shaneshot]

If you use the Ryan Cleckner methods including and especially the cheek rest you find that it is very difficult to hold the rifle securely and NOT have the cross hairs be plumb/level...you will not have to move/shuffle/adjust/compensate to get the right hold to be consistently plumb/level...when the combination of scope canting and cheek rest is dialed in it is hard to not be right on...

This is where my thinking goes and where leveling the scope to the action doesn't make sense to me. In my head I can see how it is important to have the SCOPE completely level when sighting it in and it be level when shooting. However if it is sighted in level why does it matter if it is level to the action? Trajectory is trajectory correct? I mean you could mount a scope 45 degrees to the side and as long as it was sighted in and shot with the scope/crosshairs level, it shouldn't matter. Help splain it to me if I'm wrong please.

 

[MeagerHair]

zommygun has it. If you want to shoot 500 to out over 1,000yds the eye doesn't lie.

In the end it is always your sight picture that is critical. Watch the videos he suggested.

 

[shaneshot]

Watched all the videos under his name as far as scopes go. Saw the how didn't see as much the why. I can understand to an extent at extreme distances. I think my theory still holds about more important to have them level when sighting in and shooting. Found the most helpful stuff at the longrangehunting.com site. They also argued for it out past the 500 yards, of which their site is based. However at 1000 yards,1 degree of cant is equal to 6" off. Ummm, I ain't capable of anything close to that with my skills and equipment. That is a very very very long distance!!!

 

[rockdrill]

This is where my thinking goes and where leveling the scope to the action doesn't make sense to me. In my head I can see how it is important to have the SCOPE completely level when sighting it in and it be level when shooting. However if it is sighted in level why does it matter if it is level to the action? Trajectory is trajectory correct? I mean you could mount a scope 45 degrees to the side and as long as it was sighted in and shot with the scope/crosshairs level, it shouldn't matter. Help splain it to me if I'm wrong please.

OK simplest way I can put it. The scope ideally needs to be mounted directly over the centre of the boreline. By levelling the crosshairs over the bore this works to keep the bullet' trajectory path near as possible down the line of the vertical crosshair at all distances.

If the scope is mounted with the crosshairs not level, when you shoot the gun your eye would naturally tend to 'level' them. The effect of this is pushing the bore offset from sightline.

Now if the gun is zeroed at a specific distance then the bullet will hit to point of aim. However at other distances it will strike off centre (in the vertical plane) so in effect you are introducing an unwanted drift.

As there is an angular relationship between the sight and the bore, this translates to a diverging deviation with increasing distance. Also height of scope above boreline can further influence this i.e the higher the mounting the more the deviation.

 

[brimic]

If the scope is mounted with the crosshairs not level, when you shoot the gun your eye would naturally tend to 'level' them. The effect of this is pushing the bore offset from sightline.

Yes.That.

I have an interesting oddball counterexample to share.
I have a clamp-on mount for a Swiss K-31 rifle which ends up mounting the scope above the right side of the receiver. This makes for a bit of a problem for a right handed shooter and the rifle has to be canted counter clockwise to bring the scope up to the eye.
The brain is very good finding plumb for some reason, so what I did when I mounted this scope is rotate the scope in the mount clockwise so that when I bring the scope up to my eye, the cross are as perfectly plumb and level as possible. The downside is that the bore axis and scope are not convergent. It works great if you sight in at one specific distance and 'set it and forget it' as you might a common deer rifle, but not so good if you want to shoot distances the rifle is capable of.

 

[ZommyGun]

That is a good example of how and why things matter or don't...!

For me...only into 22s with scopes...but I think the important thing in my case is making sure that both windage and elevation are as close to perfectly centered in the scope's adjustment range as possible at the longest distance that really matters to me...

Depending on the height of the scope's eye level relative to the center of the bore...that might mean adding shims in the rear or having a +Xmoa tip off rail...and that rail/ring combo might need lapping for windage to get the scope's bore in line with the barrel bore...