range calculation on variable power scopes?

[Vtec44]

At which zoom rating do you use to calculate the range? I did a quick search but couldn't find any info. TIA.

[Barney Gumble]

Usually it's the highest power, but it should say for sure in the owner's manual for your scope.

[Vtec44]

thanks, now I just need to go and find the manual. lol

[esskay]

Also depends on whether the scope is front or rear focal plane.

[Vtec44]

If it's refering the to reticle, then I assume mine is rear focal plane since it remains the same size to me when I zoom in or out.

[rksimple]

What kind of scope is it?

[CSACANNONEER]

Usually it's the highest power, but it should say for sure in the owner's manual for your scope.

I would not trust this to be the case! You need to check the manual or ask the manufacturer. I know that my NF 5.5-22 NXS, is set up to read ranges on 22X. But my 8-32 NXS is also set up to range at 22X not 32X! So, I'd suggest doing a little more research on your exact scope.

[ReconDoc242]

check the manual. Say your scope is 8-16x30...
The scope could have calculations done only at 8...or perhaps at 8 and 16.
The only way to know is to check with the manual or scope's manufacturer.

[Vtec44]

It's a cheap Barska scope, since I'm just learning the basics and do not want to drop the money on something I don't know how to use properly yet.

I sent them an email

Hello there,



I recently purchased a Contour rifle scope, model # AC10634. Since it's variable power, a which zoom rating do I need to set it at to do calculate using the mil plex reticle? Thank you in advance for your help.

Their reply

Hello James,

Thank you for contacting Barska. We received the information regarding the mil-plex reticle. I have attached it in this e-mail. If you have any questions, please let us know. Thank you.

Best Regards,

With an attachment.

Since obviously I have very limited knowledge on scopes, and was expected a different/simpler answer, what does this mean?

[Clodbuster]

It means that from the data they sent you...the correct setting to range on your 3-9x scope reticle is somewhere around 10X....

At 100 yds, the space between 2 of your tick marks should be 3.6 inches.

There is a sticky on the top of this forum you should read.


Clod

It's a cheap Barska scope, since I'm just learning the basics and do not want to drop the money on something I don't know how to use properly yet.

I sent them an email



Their reply


With an attachment.

Since obviously I have very limited knowledge on scopes, and was expected a different/simpler answer, what does this mean?

[Vtec44]

It means that from the data they sent you...the correct setting to range on your 3-9x scope reticle is somewhere around 10X....

At 100 yds, the space between 2 of your tick marks should be 3.6 inches.

There is a sticky on the top of this forum you should read.


Clod

Yeah I read it prior to sending in the question but didn't get it but I just read it again. Based on what you said, and looking at the chart I received, I assume that 3.6" the standard for the distance between 2 mil dots at 100 yards. As long as the scope is set that whatever zoom power to get close to that standard at 100 yards, use that to calculate the range. I hope I got it right, thanks.

[Clodbuster]

Barska most likely used a 10x ranging reticle in your scope to save on cost. So even though they say it's a mil dot scope, it's not. A mil is one thousandths of an inch. In the case of ranging by the mil dot system, it is 1 yard (36 inches) at 1000 yards. So at 100 yards, you get 3.6 inches,

Understand the concept and methodology of ranging, and you can use the table they sent you for accurate calculation of ranges. It just won't be based on the same numbers used by a mil-dot scope.

At 100yds (probably at 9x), you can round of the space between the dots to 4", instead of 3.5". If you divide the space between your marks by 4, then each is 1". This actually makes it an easier calculation to do in your head.

Just to verify the mfg #, next time you are at the 100yd range, cut a piece of colored tape to 3.9" and adjust your scope's zoom to see at which setting the tape just fits between your marks.

Clod

Yeah I read it prior to sending in the question but didn't get it but I just read it again. Based on what you said, and looking at the chart I received, I assume that 3.6" the standard for the distance between 2 mil dots at 100 yards. As long as the scope is set that whatever zoom power to get close to that standard at 100 yards, use that to calculate the range. I hope I got it right, thanks.

[Vtec44]

Just to verify the mfg #, next time you are at the 100yd range, cut a piece of colored tape to 3.9" and adjust your scope's zoom to see at which setting the tape just fits between your marks.

Clod

Good idea, thanks for the tip.