The Firing Line Forums

Go Back   The Firing Line Forums > The Skunkworks > Gear and Accessories

Reply
 
Thread Tools Search this Thread
Old August 23, 2019, 05:08 PM   #1
Bart B.
Senior Member
 
Join Date: February 15, 2009
Posts: 8,927
What moves up?

When you twist your scope's elevation knob in the direction arrowed "UP," what moves up on target when you regain the sight picture?

* Line of fire; point of bullet impact.

* Line of sight; point of aim.

I ask 'cause I think March scopes' instructions in their manuals are wrong.

Last edited by Bart B.; August 26, 2019 at 07:40 PM. Reason: Better clarity
Bart B. is offline  
Old August 23, 2019, 05:14 PM   #2
MTT TL
Senior Member
 
Join Date: October 21, 2009
Location: Quadling Country
Posts: 2,780
Quote:
When you twist your scope's elevation knob in the direction arrowed "UP," what moves up on target?
Nothing, The target does not move.
__________________
Thus a man should endeavor to reach this high place of courage with all his heart, and, so trying, never be backward in war.
MTT TL is offline  
Old August 23, 2019, 05:40 PM   #3
zukiphile
Senior Member
 
Join Date: December 13, 2005
Posts: 4,475
Quote:
Originally Posted by Bart B.
When you twist your scope's elevation knob in the direction arrowed "UP," what moves up on target?
My approach isn't very sophisticated. I never look at the directions on the knob. I assume that if I turn a knob clockwise the reticle will move in the direction of the knob and the point of impact will appear to move in the opposite direction relative to the reticle.

If I'm wrong, that gets obvious pretty quickly.
zukiphile is offline  
Old August 23, 2019, 05:47 PM   #4
Bart B.
Senior Member
 
Join Date: February 15, 2009
Posts: 8,927
Quote:
Originally Posted by zukiphile View Post
I assume that if I turn a knob clockwise the reticle will move in the direction of the knob and the point of impact will appear to move in the opposite direction relative to the reticle.

If I'm wrong, that gets obvious pretty quickly.
Are you thinking if the elevation knob is turned clockwise and moves down, the reticle will move down on the target and bullet impact will be further above point of aim?
Bart B. is offline  
Old August 23, 2019, 05:57 PM   #5
zukiphile
Senior Member
 
Join Date: December 13, 2005
Posts: 4,475
Quote:
Are you thinking if the elevation knob is turned clockwise and moves down, the reticle will move down on the target and bullet impact will be further above point of aim?
In my model, turning the elevation knob clockwise will raise the reticle relative to the point of impact. I imagine a stationary screw that pulls the reticle up when turned clockwise, and pushes it down when turned counter-clockwise.

On most of my scopes, that works.
zukiphile is offline  
Old August 23, 2019, 07:17 PM   #6
Bart B.
Senior Member
 
Join Date: February 15, 2009
Posts: 8,927
Quote:
Originally Posted by zukiphile View Post
In my model, turning the elevation knob clockwise will raise the reticle relative to the point of impact. I imagine a stationary screw that pulls the reticle up when turned clockwise, and pushes it down when turned counter-clockwise.
Twist the knob one full turn watching it move to see which way it goes.

Twist back one full turn; again, watching.
Bart B. is offline  
Old August 23, 2019, 07:48 PM   #7
cw308
Senior Member
 
Join Date: September 2, 2010
Location: Plainview , Long Island NY
Posts: 3,863
Looking through the scope your bullet hits low , if you look through the scope while moving your dial UP you will see your horizontal hair lower to the bullet hole
cw308 is offline  
Old August 23, 2019, 09:11 PM   #8
zukiphile
Senior Member
 
Join Date: December 13, 2005
Posts: 4,475
Quote:
Twist the knob one full turn watching it move to see which way it goes.

Twist back one full turn; again, watching.
That's how I confirm it.

I have a prismatic I like a lot, but it works the other way. Even though I know it works contrary to the dominant pattern, I adjust in the wrong direction about half the time.
zukiphile is offline  
Old August 23, 2019, 09:38 PM   #9
cslinger
Senior Member
 
Join Date: July 14, 2002
Location: Nashville, TN
Posts: 2,046
The bullet impacts move in the direction desired.

So you take aim at a fixed point. (Center Of target for example). Fire 3-5 rounds. See where they fall in relation to where you are aiming.

Then changed the scope the correct number of clicks you want the group to go. If the group fell up and right of the target you want to move it down and left for example.

Fire a new group at the same fixed target. Adjust again as necessary until your group is landing where you want it under your reticle.
__________________
"Is there anyway I can write my local gun store off on my taxes as dependents?"
cslinger is offline  
Old August 24, 2019, 08:26 AM   #10
Bart B.
Senior Member
 
Join Date: February 15, 2009
Posts: 8,927
Zukiphile, what make and model is your prism sight?
Bart B. is offline  
Old August 24, 2019, 09:40 AM   #11
zukiphile
Senior Member
 
Join Date: December 13, 2005
Posts: 4,475
Bart, the one to which I am referring was marketed by Monstrum, an outfit that can fairly be associated with "airsoft". It's a 2x with a sort of VCOG reticle. It sits on a 22lr Lothar Walther and has "Monstrum" in big white letters on one side. https://monstrumtactical.com/s232p-2...roduct-reviews They might as well have Printed "Cheap" instead. It's clear and makes nice groups on the LW.

But...

The reticle moves in a direction opposite the way I described above. In practice this simple reversal is confounding.

For what I paid, I can live with that, but it's not the same end of the market as your March.

Last edited by zukiphile; August 24, 2019 at 10:38 AM.
zukiphile is offline  
Old August 24, 2019, 12:17 PM   #12
reynolds357
Senior Member
 
Join Date: December 10, 2012
Posts: 6,165
Line of sight.
reynolds357 is offline  
Old August 25, 2019, 07:49 AM   #13
Bart B.
Senior Member
 
Join Date: February 15, 2009
Posts: 8,927
When you twist your rear aperture sight's elevation knob in the direction arrowed "UP," what moves up on target?

* Line of fire; point of bullet impact.

* Line of sight; point of aim.
Bart B. is offline  
Old August 25, 2019, 09:13 AM   #14
reynolds357
Senior Member
 
Join Date: December 10, 2012
Posts: 6,165
Line of sight. Point of aim. It's a no brainier.
reynolds357 is offline  
Old August 25, 2019, 09:56 AM   #15
Don Fischer
Senior Member
 
Join Date: March 2, 2017
Posts: 1,868
Not so sure I understand the question. If it's what I'm thinking, the thing that moves is the strike of the bullet. If it's what way do the crosswire's move, not a clue, never worried about it so long as the strike of the bullet moved.
Don Fischer is offline  
Old August 25, 2019, 10:22 AM   #16
zukiphile
Senior Member
 
Join Date: December 13, 2005
Posts: 4,475
Quote:
Originally Posted by Bart B.
When you twist your rear aperture sight's elevation knob in the direction arrowed "UP," what moves up on target?

* Line of fire; point of bullet impact.

* Line of sight; point of aim.
Quote:
Originally Posted by reynolds357
Line of sight. Point of aim. It's a no brainier.
It's actually the opposite on an A2 rear aperture. The "up" arrow points clockwise. Turning that wheel clockwise raises the rear aperture. As it rises, the point of impact gets higher relative to the point of aim.

Last edited by zukiphile; August 25, 2019 at 10:59 AM.
zukiphile is offline  
Old August 25, 2019, 11:32 AM   #17
LeverGunFan
Senior Member
 
Join Date: August 25, 2007
Location: Indiana
Posts: 407
If you change your settings without moving the firearm -

Moving the rear sight or aperture "up", the front & rear sight alignment will move down on the target, prompting you to elevate the muzzle which moves the bullet impact up.

Rotating the scope elevation knob "up" will move the reticle down on the target, prompting you to elevate the muzzle to move the bullet impact up.

In both cases, changing the elevation in the "up" direction moves the sighting element (line of sight) down on the target.
__________________
Support the Second Amendment Foundation and the Firearms Policy Coalition

Last edited by LeverGunFan; August 25, 2019 at 04:16 PM.
LeverGunFan is offline  
Old August 25, 2019, 02:07 PM   #18
reynolds357
Senior Member
 
Join Date: December 10, 2012
Posts: 6,165
Quote:
. It's actually the opposite on an A2 rear aperture. The "up" arrow points clockwise. Turning that wheel clockwise raises the rear aperture. As it rises, the point of impact gets higher relative to the point of aim.
You are missing it. If you move a sight, front or back, up or down; What changes? Rifle is on a linear bearing sled, you move sight. What changed? Point of impact didn't change, the rifle is locked down. POI does not change until you move the rifle.
reynolds357 is offline  
Old August 25, 2019, 02:11 PM   #19
cw308
Senior Member
 
Join Date: September 2, 2010
Location: Plainview , Long Island NY
Posts: 3,863
By looking through your scope and moving your crosshairs to the point of impact without moving the rifle position is the procedure . They can word it anyway they want , I'm sure everyone can figure out how to adjust . Even with a type of. Now setting up the scope , mount and rings is another animal and harder to do correctly even with good instructions .
cw308 is offline  
Old August 25, 2019, 03:38 PM   #20
zukiphile
Senior Member
 
Join Date: December 13, 2005
Posts: 4,475
Quote:
Originally Posted by Reynolds357
Line of sight. Point of aim. It's a no brainier.
Quote:
Originally Posted by Reynolds357
Quote:
It's actually the opposite on an A2 rear aperture. The "up" arrow points clockwise. Turning that wheel clockwise raises the rear aperture. As it rises, the point of impact gets higher relative to the point of aim.
You are missing it. If you move a sight, front or back, up or down; What changes? Rifle is on a linear bearing sled, you move sight. What changed? Point of impact didn't change, the rifle is locked down. POI does not change until you move the rifle.
Note the underlined language.

Bart's question isn't whether an immobilized rifle moves when the sights are adjusted. Rather the inquiry is the direction in which they change in response to adjustment. It isn't a trick question.

Complicating the answer is that some manufacturer's seemingly mean different things by "up" and "left", or don't seem to have right hand threads in the adjustment mechanisms.
zukiphile is offline  
Old August 25, 2019, 05:57 PM   #21
Bart B.
Senior Member
 
Join Date: February 15, 2009
Posts: 8,927
I may have to edit my query.

Thanks to all respondents' comments. Didn't think of all the complications.
Bart B. is offline  
Old August 25, 2019, 07:34 PM   #22
zukiphile
Senior Member
 
Join Date: December 13, 2005
Posts: 4,475
Bart, for what it's worth, I just checked an old Bushnell that has caps marked the same way March marks its caps.

The direction on these caps are for point of impact. The windage cap indicates clockwise is "left". I turn it clockwise and the reticle moves right, which would put the point of impact to the left.

This is part of why I stopped looking at lense cap instructions. I think your conclusion that the March instructions have it reversed is correct.
zukiphile is offline  
Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 06:59 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2021 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent: thefiringline.com
Page generated in 0.11166 seconds with 8 queries