Scope Leveling; Instruction that ran counter to everything I thought I knew

[wapitibob]

It still applies. A canted rifle with a plumb to ground scope will still need an offset entered into the solver to correct for the cant. If you don't there will be horizontal error just as in purely canting the rifle. It may be different with the level scope but there will still be error if not corrected for.

agreed

 

[omicron1792]

It still applies. A canted rifle with a plumb to ground scope will still need an offset entered into the solver to correct for the cant. If you don't there will be horizontal error just as in purely canting the rifle. It may be different with the level scope but there will still be error if not corrected for.

Isn’t that true for all long range shots? It’s just a math problem. Yes, this adds another variable. But it can be solved for just like all the other multitude of variables.

If it puts shooter in a more natural firing position it might be worth the other variable.

I relate this to a golf swing or throwing a football. For years coaches tried to “correct” poor mechanics in both at all costs.

Now, they correct some but allow others to continue if they are getting good results. Look at Scottie shefflers swing or Patrick mahomes throws. In the past some coach would have ruined them trying to retrain them to the “standard.” Thank God both continued with tweaking only of their flaws.

 

[BBob]

However it doesnt address the horizontal portion of error caused by the height over bore angle(s) introduced by offsetting the scope from the vertical plane of the barrel in the first place.

This is exactly why the offset function in AB and Shooter exists.

 

[mxgsfmdpx]

A bit of a red herring, but related to some comments when scrolling through this thread...

In having shot with and/or instructed multiple hundreds of shooters over the years, I can tell you that without a doubt the least safe, poorly trained, and lack of competency after day 1 of instruction places current and ex military members in dead last place overall. If you think our military is churning out Bucky Barnes on a whim you are sadly mistaken. My youngest brother received some "expert level" marksmanship badge in the army back in the early 2000's and he is the first to admit that he sucked, and still sucks at shooting because he never does it anymore.

The most effective and repeatable shooters after instruction, on average, are females aged 20ish to 50ish.

 

[Shortschaf]

This is exactly why the offset function in AB and Shooter exists.

AB cannot account for a scope that is out-of-plumb with a rifle bore. The sight-in offset function does not work that way do anything in the app

 

[Marbles]

It still applies. A canted rifle with a plumb to ground scope will still need an offset entered into the solver to correct for the cant. If you don't there will be horizontal error just as in purely canting the rifle. It may be different with the level scope but there will still be error if not corrected for.

No, it is discussing two different things. Result of a horizontal offset from POI doesn't chang that.

The error induced by an offset scope is a fixed angular error at all ranges. The error induced by a scope out of plumb is a variable angler error that changes as you dial.

Mathematically simple example. If you cant the scope at 45 degrees then every 1 mil of elevation adjustment up will move the impact point up 0.5 mils up and 0.5 mils lateral.

The first key to avoid

So many of these dumb arguments

is to know what is being discussed.

Mindlessly quoting things one doesn't understand, while a favorite pass time of mine when it comes to @Formidilosus , is not particularly helpful. Now, I'm going to get back to loading TMKs in my 22 LR for an upcoming elephant hunt while chugging Kool aid.

 

[Bugger]

edit, cancelled that thought. I was thinking about just the zero angle between the two styles and not the compounding effect of scope offset.

 

[BBob]

AB cannot account for a scope that is out-of-plumb with a rifle bore. The sight-in offset function does not work that way

If you cant a rifle the scope is not mounted directly over the bore of the barrel anymore.

What exactly does AB's description of Sight Offset mean or do then??? Please tell.

 

[mxgsfmdpx]

It's official, I caught up on 6 pages. The surveyor in me is going to have to just stay out of this one... YIKES!

 

[mt terry d]

Is there better training than what the best military snipers in the world are getting? Maybe you should volunteer to set up better training ..........

Surprised someone hasn't thought of that already.

Oh, wait........

nevermind

 

[Macintosh]

I believe this is the setting in AB:




It is grouped with the height over bore so it seems to be “measurement to the side of bore”. If it isnt what’s being discussed, what is it?

 

[Shortschaf]

If you cant a rifle the scope is not mounted directly over the bore of the barrel anymore.

What exactly does AB's description of Sight Offset mean or do then??? Please tell.

View attachment 783080

Input a scope offset of something crazy like 6" and run the calc. It doesnt do anything to the result

I'll edit my above comment. I agree that that function SHOULD BE the solution to the problem posed by the OP, based on description you shared. I simply have noticed that it does nothing at all to the calculator

Having agreed with your point, it would be very difficult to accurately measure your scope cant and then put in the scope-offset accordingly. Far simpler to just mount it close to plumb with the bore

 

[Dobermann]

Not sure that your post helps the OP, so you may want to expand on the story with Accuracy 1st.

Some of the story is in the public domain for those who want to look. Some is not.

It's not something I'm particularly interested in, but it is relevant when people start quoting that source.

 

[BBob]

I agree that that function SHOULD BE the solution to the problem posed by the OP, based on description you shared. I simply have noticed that it does nothing at all to the calculator

I do not have AB but I do however have Shooter. If you add a sight offset into Shooter it most definitely affects horizontal adjustments.

 

[BBob]

It is grouped with the height over bore so it seems to be “measurement to the side of bore”. If it isnt what’s being discussed, what is it?

That’s exactly what it is or what it is supposed to be.

 

[Shortschaf]

I do not have AB but I do however have Shooter. If you add a sight offset into Shooter it most definitely affects horizontal adjustments.

Despite all the odds, I learned something from this thread. Thanks, never heard of the Shooter app. They clearly do something right that AB Mobile does not

 

[RockAndSage]

I can't believe some of the stuff I'm reading in this thread, I need eye bleach.

It's amazing how much truly stupid $h*t starts on a flat range by some charismatic instructor, that becomes virulent through the shooting community, crippling it by convincing themselves its awesome, that only truly starts to die the brutal death it so rightfully deserves when beaten in the face by the 2x4 of unpredictable reality.

Flat range does not equal field realities.

It took the entire GWOT up until the late teens to kill off so much stupid shooting $h*t that became endemic in the 1990s and early 2000s. This qualifies. It's dumb as hell.

Level and true the g*ddamned rifle and scope and bubble level to the g*ddamned direction of gravity the g*ddamned bullet is governed by, and stop making it complicated. That's the only thing that's repeatable in the realities of the field.

 

[5811]

I can't believe some of the stuff I'm reading in this thread, I need eye bleach.

It's amazing how much truly stupid $h*t starts on a flat range by some charismatic instructor, that becomes virulent through the shooting community, crippling it by convincing themselves its awesome, that only truly starts to die the brutal death it so rightfully deserves when beaten in the face by the 2x4 of unpredictable reality.

Flat range does not equal field realities.

It took the entire GWOT up until the late teens to kill off so much stupid shooting $h*t that became endemic in the 1990s and early 2000s. This qualifies. It's dumb as hell.

Level and true the g*ddamned rifle and scope and bubble level to the g*ddamned direction of gravity the g*ddamned bullet is governed by, and stop making it complicated. That's the only thing that's repeatable in the realities of the field.

What if I introduce just enough cant to cancel out the coriolis effect and spin drift?

 

[wind gypsy]

Hurts my brain to discuss this again. This table is a helpful illustration of what matters.

 

[Macintosh]

Thanks, Ive never seen that chart. It sort of confirms—yes, it creates error…but its likely small enough error that it’s less than the resolution of the scope (.25moa or .1mil).
So in my mind the question becomes not WHETHER there is error as a result—this clearly creates error that needs to be added on top of all the other sources of error—but is getting a “better fit” across enough positions and situations enough to more than offset that error? As a longtime student of shotgun gun fit I think its possible, if unlikely. In other words if you introduce .02mils of error, can you ON AVERAGE shoot .03+ mils better as a result? Seems like something that with specific conditions and a “pro” coach could be an asset, but that 99% of folks would only be guessing at, and you’d need a lot of rounds in a very highly controlled environment to determine either way.


I dont think I’ll stop leveling the rifle.