Scope temperature shift fixes

[JEFFPPC]

I have one question nagging me. So you focus with your parallex knob looking thru the atmosphere and come up with a distance. So if your go into the sun or conversley the shade or the temp changes the atmospheric condition has now changed. So looking thru it and focusing to it your going to get a different number. It's very common at 100 yards or 1000 yards every time you come to the bench you readjust your parallex but often your POI is not changed. So your dial gives you a different number because you adjusted To The Condition. . That makes sense to me. If the scope is physically changing internally dimensionly how could it Not change POI and some say it doesn't.

 

[JEFFPPC]

Temperature affects the way field target shooters use a scopes parallax adjustment to determine distance - the air volume in the scope tube IS affected by pressure changes from temperature changes so the scope doesn’t focus the same way when adjusting for parallax

And that change is happening in the air the entire distance to the target. So when you adjust to it you will get a different number. Your trying to make the scope to donating it is not designed for.

 

[JEFFPPC]

I don't wish to argue especially since I don't shoot FT but I think you guys are using the scope as a whipping boy because your trying to make it be something it was never intended to be . So you guys shoot a tough discipline, many very well, I will retreat, those who compete have my respect.

 

[cavedweller]

I don't wish to argue especially since I don't shoot FT but I think you guys are using the scope as a whipping boy because your trying to make it be something it was never intended to be . So you guys shoot a tough discipline, many very well, I will retreat, those who compete have my respect.

You are correct - we are using scopes in a way they were never intended to be used, yet that’s the game of field target.
Don’t ask me why or how this came to be, but someone may be able to shed some historical light on how this came to be. Currently we / I take a scope that can focus as close as 10 yards and using the parallax adjustment I mark a large parallax wheel at 1 yard increments for point of focus out to 55 yards. You really need to try field target as it’s really quite fun AND very challenging!
Notice the large ranging wheel in the picture

 

[cavedweller]

We use distance to determine poi based on actual shots fired at known distances or also using ballistic programs like StrelokPro; ideally the APP dope matches or actual shots taken dope. Anyway, come visit a field target event - great people!

 

[BackStop]

@BackStop - come visit us in pensacola Fl 1st Saturday of the month at Santa Rosa shooting center and we will introduce you to field target

I truly wish I could...

Thanks!

All my best!

Kerry

 

[cavedweller]

Simple towel or sunshade of some kind over the scope when not in use.

Or if you have the coins get the March highmaster series scopes.

Still shift in direct sunlight

 

[qball]

Still shift in direct sunlight

Learned over last couple of years is that each scope has shift at different internal temp range/points. Example is my sightron S8 seems to range shorter past 40 yards with temp over 90-95 degrees. Having a shade helps prevent extreme temp shift but even with shade the internal temp still will normalize to ambient after some time and shift if the temp range is reached internally.

Never used high master scopes before but I assume they will still shift if under direct sunlight due to extreme high internal temp. They claimed the high master models will not get temp shift due to construction and material but they didn’t specify at what temp range, a black scope can get really hot in direct sunlight.

 

[Ta-Ta Toothie]

March main body is 4mm thick, so that will just slow it down some. I just got a High Master and it's already heading back for an exchange. They scratched the hell out of the inner walls installing the internals.

 

[cavedweller]

March main body is 4mm thick, so that will just slow it down some. I just got a High Master and it's already heading back for an exchange. They scratched the hell out of the inner walls installing the internals.

how did you figure that out?

 

[Ta-Ta Toothie]

how did you figure that out?

The thickness or the damaged caused?

 

[Ta-Ta Toothie]

If you're referring to thermal expansion, I got that information from others experience.