Parallax adjustment for long range.

[Macmathews]

I have a fairly nice range in my back yard when the crops are all off..
Set-up with a shooting shack and about 1300Yards to play..

I can do really well with my Rem 5R in 308 between 100 and 400 yards.. Well under MOA

but when I start to push the range out past 600 yards things fall apart..
Recently shot a 5 shot group of about 10" at 700 Yards.. ( I'm not happy with that..) and believe the rifle and my reloads are capable of better..

My issue may be due to parallax adjustment..
I cannot follow low lights on-line explanation of moving your head side to side (up down) to get my reticle to remain on target..
My scope is a SS 5-20 HD

#1 - How much should I really be moving head. I don't believe I am moving so much to get shadowing..
#2 - How much could this adjustment be off compared to the range noted on the adjustment.. Eg.. 200 yard setting when shooting 800 yards ?
#3 - I will pay more attention to my cheek weld and see if this could be the culprit..
#4 - I can move my head up and down with ZERO movement..But when moving side to side.. I see large reticle movement



Going to my hunt camp this weekend where we can shoot as far as wanted from a perched position over a snow covered LAKE..
It make's corrections and sightings EASY..
And is a blast when shooting balloons and steel ect..


Kyle

 

[Notso]

I have a fairly nice range in my back yard when the crops are all off..
Set-up with a shooting shack and about 1300Yards to play..

I can do really well with my Rem 5R in 308 between 100 and 400 yards.. Well under MOA

but when I start to push the range out past 600 yards things fall apart..
Recently shot a 5 shot group of about 10" at 700 Yards.. ( I'm not happy with that..) and believe the rifle and my reloads are capable of better..

My issue may be due to parallax adjustment..
I cannot follow low lights on-line explanation of moving your head side to side (up down) to get my reticle to remain on target..
My scope is a SS 5-20 HD

#1 - How much should I really be moving head. I don't believe I am moving so much to get shadowing..
#2 - How much could this adjustment be off compared to the range noted on the adjustment.. Eg.. 200 yard setting when shooting 800 yards ?
#3 - I will pay more attention to my cheek weld and see if this could be the culprit..


Going to my hunt camp this weekend where we can shoot as far as wanted from a perched position over a snow covered LAKE..
It make's corrections and sightings EASY..
And is a blast when shooting balloons and steel ect..


Kyle

1. Not much. Just a little bit of head movement will tell you if the reticle is moving. I don't know how to quantify it, but literally just barely off the stock slightly up & down. I usually just barely nudge my head up and down and can see if the reticle stays on tgt or not fairly quickly.

2. The number on your scope parallax knob and the actual range can differ by a considerable amount. It is not uncommon on my S&B to be shooting at 500m and the parallax knob at 700ish or something like that. Other times they are fairly close. The head movement test is the final arbiter of whether its correctly adjusted, I think.

Here's what I do (take it FWIW). I turn the knob to purposefully be out of focus above and below, then stop when it just comes into focus from either end. Once its perfectly in focus, then I move my head slightly to see if the reticle says on target. If its not, then I move it slightly further into the focused area and try again. Try to put the reticle on something VERY definitive (like the center of the bull or a dot) so its obvious if it moves when you move your head. And have the gun very steady.

Essentially I'm in my full normal shooting position (bench or prone) with the rifle braced just as if I was about to shoot on a bipod and rear bag - then you just barely move your head up and down and you can see if the reticle shifts or not. To me its fairly obvious when its not adjusted correctly.

Someone smarter than me please jump in and correct me if I'm wrong. That's what I was taught and it seems to work for me.

 

[Deadshot2]

You don't want to move your head so much it's actually causing the rifle to move. I first make sure the rifle is solid in the rear bag and bipod loaded. Then with a slight up/down of my Eye, by rocking my head on the cheek and trying not to move the rifle is all I need.

My scope has NO graduations on the parallax adjustment knob. Keeps everyone from worrying about the numbers. The parallax (focus) adjustment is just that, not a ranging device.

 

[Macmathews]

Ok...
here's another piece to the puzzle.
I will add to above as well..

I can move my head up and down with ZERO movement..But when moving side to side.. I see large reticle movement
Seems maybe like user error ?

Kyle

 

[Deadshot2]

Ok...
here's another piece to the puzzle.
I will add to above as well..

I can move my head up and down with ZERO movement..But when moving side to side.. I see large reticle movement
Seems maybe like user error ?

Kyle

It's easier to move the rifle stock sideways when moving your head. Unless you have the side of the stock up against an immovable object that is, like the sandbag under the stock. This ease of movement, side-side, is what causes most errors in shooting as well. The smallest "wiggle" on that end causes huge errors at long range. Simple math.

 

[nfoley]

Also make sure you are getting clear sharp edges in your scope prior to breaking the shot - if your eye is lined up (exactly)with the optical axis there is no parallax. Further off the axis you go worse parallax gets.
BTW it may not be parallax you are struggling with. Environment becomes a bigger factor the farther you shoot.
Shooting 5 shot groups of 10" at 700 yds is not bad - wouldn't say you were falling apart. Nice shooting.

 

[Macmathews]

It's easier to move the rifle stock sideways when moving your head. Unless you have the side of the stock up against an immovable object that is, like the sandbag under the stock. This ease of movement, side-side, is what causes most errors in shooting as well. The smallest "wiggle" on that end causes huge errors at long range. Simple math.

So do I have to check both side to side and up/down.. Movement or will just 1 suffice ?
Maybe I am moving the stock as noted ? !

Kyle

 

[Macmathews]

Also make sure you are getting clear sharp edges in your scope prior to breaking the shot - if your eye is lined up (exactly)with the optical axis there is no parallax. Further off the axis you go worse parallax gets.
BTW it may not be parallax you are struggling with. Environment becomes a bigger factor the farther you shoot.
Shooting 5 shot groups of 10" at 700 yds is not bad - wouldn't say you were falling apart. Nice shooting.

Thanks..
I just have dreams of walking up on 5 shot groups of 5" @ 1000 YARDS..
My issue is I have no friends into shooting and the ones that do shoot. Rely 100% on me..
So my learning is slow in the practical sense.

Kyle

 

[Deadshot2]

So do I have to check both side to side and up/down.. Movement or will just 1 suffice ?
Maybe I am moving the stock as noted ? !

Kyle

Parallax is a function of the optics of the scope so if one's good, so's the other unless you have a really bad (as in cheap quality) scope.

A very important reminder, make sure your eye piece is properly adjusted so it's only focused on the reticle. Do not try and use it to focus your target view.

For a more perfect adjustment set up a plain white target alongside your 100 y target when you're zeroing. Turn the parallax adjustment to infinity. Then focus the reticle itself against the plain white background It's a lot easier to throw everything downrange out of focus so the only object your eye focuses on is the reticle. Carefully adjust the eyepiece for the sharpest image possible.

If your "reticle focus" is off, so can your parallax, even after adjusting it with side knob or front lens. Once the eyepiece is adjusted properly you may only have to do it when the scope has undergone some wide temperature changes. Maybe not even then.

 

[Macmathews]

Parallax is a function of the optics of the scope so if one's good, so's the other unless you have a really bad (as in cheap quality) scope.

A very important reminder, make sure your eye piece is properly adjusted so it's only focused on the reticle. Do not try and use it to focus your target view.

For a more perfect adjustment set up a plain white target alongside your 100 y target when you're zeroing. Turn the parallax adjustment to infinity. Then focus the reticle itself against the plain white background It's a lot easier to throw everything downrange out of focus so the only object your eye focuses on is the reticle. Carefully adjust the eyepiece for the sharpest image possible.

If your "reticle focus" is off, so can your parallax, even after adjusting it with side knob or front lens. Once the eyepiece is adjusted properly you may only have to do it when the scope has undergone some wide temperature changes. Maybe not even then.

Wow..
All great info I had NO idea about !

Kyle

 

[Northman623]

One more point that is big when trying to squeeze out a little more accuracy. When your eye is at the back of the eye box, you will see a dark ring begin to appear around the outer edge of the site picture, a lot of people think this is bad its not a clear image right. Well it is a good thing if you make all the edge equal thickness, this insures that you are viewing the exact optical center. If you repeat this each shot your groups will begin to shrink. This will also help to eliminate parallax issues. I know all the above is a lot to take in so start taking notes to the range for your shot setup.

 

[Macmathews]

One more point that is big when trying to squeeze out a little more accuracy. When your eye is at the back of the eye box, you will see a dark ring begin to appear around the outer edge of the site picture, a lot of people think this is bad its not a clear image right. Well it is a good thing if you make all the edge equal thickness, this insures that you are viewing the exact optical center. If you repeat this each shot your groups will begin to shrink. This will also help to eliminate parallax issues. I know all the above is a lot to take in so start taking notes to the range for your shot setup.

Not really that much to take in.. As I can comprehend all of it.
Have never shot around anybody better than myself and have not read any of the above on this forum..

1 year ago.. I was searching for load accuracy.. I believe with .5 MOA 5 shot groups at 400 yards.. I am there.. I just need more trigger time and understanding !

Thanks for your help

Kyle