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Scope temp shift  


josh3rd
(@josh3rd)
Joined: 3 years ago
Posts: 236
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I know about the possibilities of ranging errors due to temperature shifts. But I wanted to know if it's usually in the same direction. 

Meaning this: Say your scope ranging accuracy changes say at 80°. And say you're ranging a target at a known 50yds. Is your scope ranging short or long?

 

Basically I just want to know if either hit or cold, do all or will all scopes mistakenly range in error in the same direction?

 

So if a scope rangers longer when cold is that how other scopes will range upon their own temp shift?


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ekmeister
(@ekmeister)
Member of Trade
Joined: 3 years ago
Posts: 695
 
Posted by: @josh3rd

I know about the possibilities of ranging errors due to temperature shifts. But I wanted to know if it's usually in the same direction. 

Meaning this: Say your scope ranging accuracy changes say at 80°. And say you're ranging a target at a known 50yds. Is your scope ranging short or long?

 

Basically I just want to know if either hit or cold, do all or will all scopes mistakenly range in error in the same direction?

 

So if a scope rangers longer when cold is that how other scopes will range upon their own temp shift?

I don't know. But, I'll take an experienced guess of sorts, based on decades of work in the residential and commercial HVAC fields, AND, personal experience in my own private world, including those as a shooter.

I'd consider each scope and rifle rig to be a unique case all unto itself. That is, just because one/my pair of them do something or other in that regard, it doesn't mean the next one/yours will do the same thing.

Why?

There are many reasons. For starters, construction methods and materials are open to a wide range of variables and change from one specimen to another--and, that doesn't even take the scope rings or mount into consideration. A scope manufacturer can totally-change what's on the inside of his scope with the same model number, for instance, and he's not under obligation to tell you about it.

What's more, I think we really have 3 pieces in play here, not 2: that's the rifle, mounting system, and scope.

Of course, those who really care like to take chance entirely out of the equation. They simply open their gun case, and let the whole rig acclimate to ambient temperature for 30 minutes, or whatever seems reasonable. Bigger difference=more time. Then theory and conjecture don't matter. You're dealing with what really is.

Since condensation can be a concern in some situations, just cracking the case open a little at first can be the way to get around that.

I learned about the 'just crack it open' technique when i was in my teens, in relation to my friend's nice, much-loved, Gibson acoustic guitar. He lent it to me, and asked me to please do that, if I was somewhere where there was a large temperature difference. He said that otherwise, the finish on the outside was subject to 'checking' (hairline cracking). 

I did what he asked, thus allowing for a gradual change, and there was never a problem. We lived in Ohio, and winter weather could be quite cold. Yet, at times, we still liked to play outdoors. You know: campfires, pretty girls, hot toddies, all that stuff.  🙂

There's my 3 cents.

(Next).


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bvan
 bvan
(@bvan)
Joined: 3 years ago
Posts: 59
 
Posted by: @josh3rd

I know about the possibilities of ranging errors due to temperature shifts. But I wanted to know if it's usually in the same direction. 

Meaning this: Say your scope ranging accuracy changes say at 80°. And say you're ranging a target at a known 50yds. Is your scope ranging short or long?

 

Basically I just want to know if either hit or cold, do all or will all scopes mistakenly range in error in the same direction?

 

So if a scope rangers longer when cold is that how other scopes will range upon their own temp shift?

No easy answer here Josh. You should map out your own scopes shift over the temperatures you expect to use it in. That's the best way to go. Springers are temperature sensitive too. Get to know your equipment and own it.

Brian


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josh3rd
(@josh3rd)
Joined: 3 years ago
Posts: 236
Topic starter  

Ed and Brian, thanks a lot brothers.


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gonzav
(@gonzav)
Joined: 3 years ago
Posts: 135
 

Josh,

Every scope is different. You must test each one for temperature sensitivity. I own two Sightrons 10-50x60, one Falcon X50, one Mueller 8-32x44 and one Leupold 35x scopes. Most of them will range longer at higher temps. It might not be true with your scope. You must test and record results on your own. Don't assume what result I get will be the same as yours. Some individual scopes will shift more than others even if they are the same brand and model.

Regards,

Leo


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josh3rd
(@josh3rd)
Joined: 3 years ago
Posts: 236
Topic starter  

Leah what I was trying to get at is if it's cold do all Scopes will most Scopes will they range short or will they range long like will one scope if it's cold rains long and another scope range short or is it like a given I'm not asking for exact numbers but I'm thinking that they would do kind of the same not the exact but cold being short and hot being long type of thing


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Knobs
(@knobs)
Joined: 3 years ago
Posts: 137
 
Posted by: @josh3rd

I know about the possibilities of ranging errors due to temperature shifts. But I wanted to know if it's usually in the same direction. 

Meaning this: Say your scope ranging accuracy changes say at 80°. And say you're ranging a target at a known 50yds. Is your scope ranging short or long?

 

Basically I just want to know if either hit or cold, do all or will all scopes mistakenly range in error in the same direction?

 

So if a scope rangers longer when cold is that how other scopes will range upon their own temp shift?

You've also got to learn how to range in light & dark conditions. Ranging shifts occur due to changes in your eye that occur in different lighting conditions.

Watch it when you're ranging a target and the foreground or side areas are very bright. I think it causes your iris to close, affecting your ranging. You'll see shooters wearing hoodies or hats with long bills & side flaps, etc, to block the light. You can also cup your hand over the side of your eye to block it out while ranging. It's important not to confuse temp shift with lighting condition shifts.

Lastly, we put so much importance on ranging that it gets into many shooters heads, messing them up. My two cents is that it's far more productive to concentrate on developing NPA, steady hold, follow through, and calling the shot accurately.

In a spring gun, if you're attempting to break the shot while drifting through the KZ, you will almost always throw a shot in the direction of drift. One has to learn through practice what an acceptable amount of movement is allowable, and this feedback is part of calling the shot.

HTH

Knobs


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josh3rd
(@josh3rd)
Joined: 3 years ago
Posts: 236
Topic starter  

Thanks knobs. All feedback is appreciated


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Gratewhitehuntr
(@gratewhitehuntr)
Joined: 3 years ago
Posts: 1030
 

The scope?

It seems to me that the gun is a much larger factor here.

 

I have nothing else to add.


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Knobs
(@knobs)
Joined: 3 years ago
Posts: 137
 

@gratewhitehuntr

It sure can be!

K


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josh3rd
(@josh3rd)
Joined: 3 years ago
Posts: 236
Topic starter  

And as for everyone else, thank you for your feedback. Much appreciated


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