Use of Spotting Scope to shoot

[Jay Christopherson]

While this is obvious to the children of the spotting scope, others may not realize it...

There are conditions where a spotting scope is nearly the ultimate tool for detecting wind changes via mirage. There are many other conditions out there where there is little or no mirage to be seen. In those cases the spotting scope can be used on adjacent targets, or environmental wind indicators, or the flags themselves. There are a few conditions out there that even the most dedicated spotting scope user will push it away and just put rounds downrange.

The winner of an F-class relay is normally the person that picks the best technique for seeing the wind under the present conditions.

Amen.

EDIT: You couldn't pay me to mess with my parallax (i.e., defocus for mirage and refocus for shoot) once I've started a string, but I know some guys that do it successfully.

 

[Turbulent Turtle]

Well I guess it is a waste of money even putting parallax adjustment on a F class scope then. Funny how it does have a huge effect on on short range and long range bench rest........ Jim

I'm sure it's my fault and I didn't make it clear enough.

We are talking about focusing the riflescope at 950 yards instead of 1000 yards. We are NOT talking about having a scope focused at 100 yards and shooting at a target 1000 yards away. I will go even further and say that I would not be surprised if most scopes on the line are probably not perfectly focused for 1000 yards. This becomes a challenge when conditions are bad are you're moving from one line to the next.

I've also found myself shooting at 1000 yards when my scope was focused at 600 yards from the prior match, or the reverse, shooting a 600 yard match with my scope left on the 1000 yard setting. Heck, I even remember a time a few years ago when I cleaned a 600 yard target twice in one day and then discovered my scope was set for 1000 yards.

If you look at an adjustable objective that has distance marks on it, even though they are not very accurate, they give you the sense of the logarithmic progression in focusing a lens. You find the same thing in a camera lens. The closer the distance to target the more adjustment is required to focus the lens on the target. Take the minimum focus distance and you will notice that to get to twice that distance, you need to adjust quite a bit, say a half turn on the AO. Doubling the distance again however, only requires a quarter turn, then doubling again, requires an eighth and so on. Going from 600 yards to 1000 is barely a movement on the lens; you go from 100 yards to infinity in less than a quarter turn. When you have a longer focal length, this movement is stretched out a bit more but it is still a logarithmic progression and remember that even in a 50X scope, the focal length for parallax adjustment is only found in the front third or the riflescope, the objective lens system and that focal length is not very long.

So yes, precise parallax adjustment is vital, critical at shorter distances (focused at 100 yards for a 200 yard target is bad,) but the criticality of precise parallax adjustment diminishes with distance so focusing at 950 yard on a 1000 yard target is inconsequential.

Please note that this does not apply quite the same way to spotting scopes; their focal length is a lot longer than a riflescope's; focusing is a lot more critical at longer distances than for riflescopes. I can immediately tell when my Kowa is focused at 600 yards and the target is at 1000 yards.

 

[johara1]

Sometime you come to Reade range when the All army and USMC. teams are there and maybe you change their mind on how to shoot long range a how to read the wind. Get your entry in early it fills up Quick....... Jim

 

[johara1]

Amen.

EDIT: You couldn't pay me to mess with my parallax (i.e., defocus for mirage and refocus for shoot) once I've started a string, but I know some guys that do it successfully.

Jay they may even be more successful if they would read the wind with a spotting scope....... Jim

 

[rardoin]

Amen.

EDIT: You couldn't pay me to mess with my parallax (i.e., defocus for mirage and refocus for shoot) once I've started a string, but I know some guys that do it successfully.

I adjust mine to 'focus' on the number board in front of the protection berm prior to firing and leave it there for the duration of that match.

 

[Depart123]

I didn't see this mentioned, but a rifle scope is designed to have a fairly large depth of field. To varying degrees, a rifle scope looks "through" mirage (for lack of a better term) better than a spotting scope. A spotting scope is designed to be somewhat more specific in what it focuses on, therefore it is easier to see mirage in slices by refocusing at different distances.

 

[XTR]

You can discuss this to death, there are times that the mirage at the targets will tell you what is going on and you can see it in the rifle scope. I've learned over the yrs to try to remember to confirm that what I see in the rifle scope matches what I just saw in the spotter if that is the condition that I'm shooting in that match.

Then there are the ranges/matches where mirage at 300 or 600 yards corresponds more to what you are seeing on the target than what you see on the targets with the rifle scope

Then there are ranges where the terrain will make things wonky. Take for example Oak Ridge. In the 2015 State Mid Range championship shooting F-TR I dropped a point out left. Flags at OR are notoriously low in usefulness. Looking in the spotter the mirage on the boards was showing a good ¼ to ½ moa left to right ???? The in my spotter I noticed that the mirage on the top of the targets was right to left. I didn't lose another on that shift, but I saw people throw 8s.

At Tullahoma the wind and flag and mirage at the targets will show a solid left to right because the wind is swirling off of the stand of trees on the left side between 900 and 1000 yards. If you dial/hold for that you may be lucky to be in the black because the wind you need to be looking at is between 300 and 600 yards down range.

If the wind gets over about 8 MPH the mirage gets flat and is of little value, shooting at Connaught or Raton with 7 or 8 MOA on your scope the spotter is good for looking at the carnage on other targets.

So, it depends

 

[Rtheurer]

Maybe we can get the F-O and FTR National Team wind Coaches to just lay down next to the shooter with another rifle scope.... since a spotting scope does not matter in reading wind conditions.....I mean there are people winning that way right?! ( sarcasm)

 

[memilanuk]

One thing I've noticed is that when I'm sitting up in a chair scoring, watching the conditions thru a spotting scope... the changes in mirage often seem a lot easier to see. I'll be watching... yup, there's a change, should push them out to a wide 9 if they don't... yep, they missed it. From the chair, I can see that stuff pretty easily.

Then I get down on the ground, and... can't see the changes worth a darn

In discussion, the theory is that as you get up a little bit off the ground - closer to where the bullet is actually flying at, and away from the ground mirage - things become a little truer. So apparently I need a 3 foot periscope on my spotting scope for when I'm shooting from position...

 

[Depart123]

If mirage is bad enough, you can read it with a 10x scope. If it is more subtle then you need a more refined instrument. I don't think it is a stretch to say that a spotter is absolutely necessary sometimes and other times not so much. But if you don't have one, you don't have the option.

 

[rardoin]

I've learned over the yrs to try to remember to confirm that what I see in the rifle scope matches what I just saw in the spotter if that is the condition that I'm shooting in that match.

That is what I try to do....shoot when they match.

 

[Dos XX]

I am a fan of using one. Took me three iterations to get the stand and head combo I like. I think you need to be able to swivel it easily without breaking position so that you can move it to a row of flags if there is no mirage or to an adjacent target if you hear some swearing down the line.

 

[XTR]

you don't need a spotting scope to know that $#!+ means add 2 rings.

 

[Mr. Ten-X]

Most of my competitive shooting involved iron sights, so I may seem a bit biased toward having a spotting scope Unfortunately, my non-shooting eye was poorly adapted by genetics for glassing mirage between shots. This meant taking the rifle down and remounting it between shots. NOT optimal by any stretch. Solid shots in 10-11 seconds after coming off the spotter kill you in switching conditions. Those that can keep the eyepiece high/tight to their non-shooting eye (as well as keeping the rifle mounted in the shoulder) and break shots inside 5-6 seconds have a distinct advantage. That is all the edge they may need in the right conditions. It isn't necessarily that they can read mirage better, shoot better or have superior firing strategy at times....

Though there have been some dynamite scores fired by the F-ers without a spotting scope, they may be leaving points in the berm. When you have a spotter with a wide field of view and a long depth of field, it will show you things that you will never see, even with the best rifle scopes made. You can see subtle mirage velocity changes that will produce lateral shots and it is far easier to correlate the mirage that really matters to the up-wind indicators that warn you of an impending change. What is happening in the mirage at the target is of little consequence because the projectile is already there and the wind/mirage changes up-range affect the bullet to a far larger degree.

Where to focus? About mid-range...600-800yds for 1000yd shooting. Of course, that depends on humidity and light levels. At least that always worked out best for the 16X Leica's that I favored because of their depth of field. Was never one to watch other targets unless I was verifying a change outside of my firing parameter.

I would never consider competing without one