Optic, reticle, and rifle leveling.

[Nathantc]

Most know that if the reticle and optic are not true with one another. Hold over and elevation adjustments will not be true. Same if the rifle/optic combination is canted. I read on here and other forums that it does not matter if the reticle is trued with the rifle's bore. I feel that if you have the rifle canted when mounting your optic, then level the optic when shooting, that the bore will be off to one side or the other of your optic (think russian firearms). So my thought is this.
If the bore is off to one side or the other of the optic, the projectile has to cover that distance to reach point of aim. Not a big deal at a fixed distance but the line of sight and line of travel will not be parallel. Ignoring bullet drop (i know they don't fly in a straight line) wouldn't the point of aim vs the point of impact be changed at varying distances.
The easiest way to explain this would be to mount a laser sight to a rifle scope. Let's say you mount the laser to the 11:30 position in reference to the reticle. Zero the laser and riflescope to 100% match each other at 100 yards. Then look at something at 50 yards, then 200 yards. Ignoring the elevation error, you WILL see the windage error im talking about. This same effect should be present if the rifle scope is not truly centered over the rifle bore, or am i missing something.

 

[Shootin Stuff]

No, the easiest way to explain is to look on this website for an article by LL himself that breaks down all of the angles and offsets and proves that they are a non issue.

As long as your reticle is kept plumb then any bore offset caused by realistic rifle cant gets lost in the noise.

 

[_Windrider_]

this has been beat to death here over the years. Here is a chart breaking it down. And here is a thread where it’s discussed. Like shooting said, the effects are marginal at best. Level reticle to gravity. That’s it.

Rifle Scopes - Scope mounting - plum, level, square and offset.

So after reading 400(ish) posts about scope mounting and leveling I had to do the math. Every time a scope mounting or leveling thread is posted it usually leads to conversations about weather the rifle needs to be level when the scope is mounted level. And sometimes is goes into weather the...

www.snipershide.com

 

[Nathantc]

after what is posted here, and what someone pointed out on another forum/thread. I now realise that i was both correct, and incorrect at the same time.
Yes there is proof that it causes a windage error. It's just so minor that by the time it would be an issue you would be beyond practical range for any rifle in existence.

 

[Shootin Stuff]

after what is posted here, and what someone pointed out on another forum/thread. I now realise that i was both correct, and incorrect at the same time.
Yes there is proof that it causes a windage error. It's just so minor that by the time it would be an issue you would be beyond practical range for any rifle in existence.

Now as a thought exercise, think about spin drift and coriolis and how a bore offset could be beneficial for cancelling their effects?