GTA

Target Shooting Matches, Discussion & Events => Field Target Gates => Hunter Class Field Target => Topic started by: Motorhead on October 25, 2017, 12:42:27 AM

Title: Some FYI on 16X scope calibration for 2018 AAFTA season & beyond
Post by: Motorhead on October 25, 2017, 12:42:27 AM
Here in a few weeks ... Post Nationals we in "Hunter Class" rifle Spring or PCP, get to use 16X scopes as a maximum.  I'm sure many with stay with there 12X optics being many scopes in use have 12x as there max magnification.

** This ONLY applies to SECOND FOCAL plane optics.  ( 1st focal plane don't matter )

As a quick recap, in calibrating your MIL-RAD / MIL-DOT scope to read at a true 12x ( generally done with higher mag scopes turned down ) or as a test if your actually getting a true 12x the test for this has been ....  8)
At a MEASURED 100 feet when your scope is accurately at 12X a Viewed ruler at the 100' distance will view at 1 mil-dot / rad to the inch.

Now that we get to use 16X in the near future we need to recalibrate to be sure we are at 16X so if using data such as Chairgun etc ... our data in becomes good DOPE data out  :-\
With 16X being 33 1/3% higher than 12X the math is simple enough to use the same 1" to the Mil-dot / Rad as viewed  :o

Tho DISTANCE now becomes 133 feet 4 inches inches to said ruler ... where when accurately at 16X,  it will view 1 inch to the Dot / Rad  ;)


Some FYI for more serious Field Target shooters or those who use holdover data etc ...

Scott

 PS.
The accuracy of doing this BEST DONE looking at @ 1 foot of ruler or more & lets say cross hair on the 6" and reading 6 dots either side for a total of 12"  ( just an example )
Title: Re: Some FYI on 16X scope calibration for 2018 AAFTA season & beyond
Post by: Scotchmo on October 25, 2017, 01:48:05 AM
Here in a few weeks ... Post Nationals we in "Hunter Class" rifle Spring or PCP, get to use 16X scopes as a maximum.  I'm sure many with stay with there 12X optics being many scopes in use have 12x as there max magnification.

** This ONLY applies to SECOND FOCAL plane optics.  ( 1st focal plane don't matter )

As a quick recap, in calibrating your MIL-RAD / MIL-DOT scope to read at a true 12x ( generally done with higher mag scopes turned down ) or as a test if your actually getting a true 12x the test for this has been ....  8)
At a MEASURED 100 feet when your scope is accurately at 12X a Viewed ruler at the 100' distance will view at 1 mil-dot / rad to the inch.

Now that we get to use 16X in the near future we need to recalibrate to be sure we are at 16X so if using data such as Chairgun etc ... our data in becomes good DOPE data out  :-\
With 16X being 33 1/3% higher than 12X the math is simple enough to use the same 1" to the Mil-dot / Rad as viewed  :o

Tho DISTANCE now becomes 66 feet 4 inches to said ruler ... where when accurately at 16X,  it will view 1 inch to the Dot / Rad  ;)


Some FYI for more serious Field Target shooters or those who use holdover data etc ...

Scott

 PS.
The accuracy of doing this BEST DONE looking at @ 1 foot of ruler or more & lets say cross hair on the 6" and reading 6 dots either side for a total of 12"  ( just an example )

1/3 greater would be 133' 4".

100 x 16/12 = 133.33

That said, a 16x scope is rarely at exactly 16x, so adjust your dope accordingly. And remember, that the distance used to check subtensions is taken from the reticle focal plane, not the muzzle.
Title: Re: Some FYI on 16X scope calibration for 2018 AAFTA season & beyond
Post by: Motorhead on October 25, 2017, 02:06:51 AM
I remember talking to you about this a month or so ago ... Must have remembered wrong about the 1/3 Less More distance ... Huh guess I'm premature in posting this being my memory is failing me  :P :P :P

So as the man(Scott H ) who loves his ranging data ... it is 133.3 ft to view 1" per Dot / Rad.

My bad ... dang age anyways  ;D ;D
Title: Re: Some FYI on 16X scope calibration for 2018 AAFTA season & beyond
Post by: Scotchmo on October 25, 2017, 02:56:10 AM
I remember talking with you about it awhile back. It can be confusing. I almost went for your explanation but something inside said "wait a minute!"

At any given range distances, dot spacing is inversely proportional to magnification. So range distance for 1 inch dot spacing is directly proportional to magnification.

As magnification increases inch/dot decreases.

At 100 yards:
10x = 3.60 in/dot
12x = 3.00 in/dot
16x = 2.25 in/dot

For 1 inch dot spacing:
10x: 100 yards/3.60 in/dot = 27.78 yards = 83'4" = 1000 inches
12x: 100 yards/3.00 in/dot = 33.33 yards = 100' = 1200 inches
16x: 100 yards/2.25 in/dot = 44.44 yards = 133'4" = 1600 inches
Title: Re: Some FYI on 16X scope calibration for 2018 AAFTA season & beyond
Post by: Gear_Junkie on October 25, 2017, 12:05:51 PM
Great info here, thanks guys!
Title: Re: Some FYI on 16X scope calibration for 2018 AAFTA season & beyond
Post by: prosportfan on September 08, 2018, 05:19:05 PM
Here in a few weeks ... Post Nationals we in "Hunter Class" rifle Spring or PCP, get to use 16X scopes as a maximum.  I'm sure many with stay with there 12X optics being many scopes in use have 12x as there max magnification.

** This ONLY applies to SECOND FOCAL plane optics.  ( 1st focal plane don't matter )

As a quick recap, in calibrating your MIL-RAD / MIL-DOT scope to read at a true 12x ( generally done with higher mag scopes turned down ) or as a test if your actually getting a true 12x the test for this has been ....  8)
At a MEASURED 100 feet when your scope is accurately at 12X a Viewed ruler at the 100' distance will view at 1 mil-dot / rad to the inch.

Now that we get to use 16X in the near future we need to recalibrate to be sure we are at 16X so if using data such as Chairgun etc ... our data in becomes good DOPE data out  :-\
With 16X being 33 1/3% higher than 12X the math is simple enough to use the same 1" to the Mil-dot / Rad as viewed  :o

Tho DISTANCE now becomes 133 feet 4 inches inches to said ruler ... where when accurately at 16X,  it will view 1 inch to the Dot / Rad  ;)


Some FYI for more serious Field Target shooters or those who use holdover data etc ...

Scott

 PS.
The accuracy of doing this BEST DONE looking at @ 1 foot of ruler or more & lets say cross hair on the 6" and reading 6 dots either side for a total of 12"  ( just an example )

thanks for that info Scott
Title: Re: Some FYI on 16X scope calibration for 2018 AAFTA season & beyond
Post by: prosportfan on September 08, 2018, 05:21:06 PM
I remember talking to you about this a month or so ago ... Must have remembered wrong about the 1/3 Less More distance ... Huh guess I'm premature in posting this being my memory is failing me  :P :P :P

So as the man(Scott H ) who loves his ranging data ... it is 133.3 ft to view 1" per Dot / Rad.

My bad ... dang age anyways  ;D ;D

So just to be positive about my hawke airmax 30 sf 4-16x, it reads a true mildot spacing at 12 or 10?  I believe its 10x because of Hawke's 10x 1/2mildot reticles?
Title: Re: Some FYI on 16X scope calibration for 2018 AAFTA season & beyond
Post by: Motorhead on September 08, 2018, 05:28:08 PM
I remember talking to you about this a month or so ago ... Must have remembered wrong about the 1/3 Less More distance ... Huh guess I'm premature in posting this being my memory is failing me  :P :P :P

So as the man(Scott H ) who loves his ranging data ... it is 133.3 ft to view 1" per Dot / Rad.

My bad ... dang age anyways  ;D ;D

So just to be positive about my hawke airmax 30 sf 4-16x, it reads a true mildot spacing at 12 or 10?  I believe its 10x because of Hawke's 10x 1/2mildot reticles?

10X
Title: Re: Some FYI on 16X scope calibration for 2018 AAFTA season & beyond
Post by: Frank in Fairfield on September 08, 2018, 05:44:49 PM
My sidewiders only go to 14X.

I set the scope at 14X, re-zeroed at 25 yards, told Chairgun, printed out a new card and shot 76% last month with the TX200...
.
Good enough for an overweight 73 year old Vietnam veteran with high blood pressure, high cholesterol, Type II Diabetes and still drinking 5-6 cups of caffeinated coffee every day. Huh?

You are right.

BTW as I write this I am at 7000 in Wyoming, shooting prairie dogs:
Title: Re: Some FYI on 16X scope calibration for 2018 AAFTA season & beyond
Post by: prosportfan on September 09, 2018, 02:52:21 PM
to everyone, thank you for all your input and responses