FT DOPE Cards for SFP Optics in Multiple Classes

[pewpewfever]

Is there a typical approach for generating DOPE cards in FT for the various classes? Seems all the popular optics are SFP, so I guess you'd need two DOPE cards for shooting at two different magnifications. Is there a typical magnification used in open class? Or would someone who also shoots Hunter class just work up a 16X DOPE card, and then only use the higher magnification in open class for rangefinding?

 

[Exitpupil]

You need to make a separate card for the different magnifications, one for 16X hunter and the other for what you want to use in open such as 35X or 40X. When transitioning from hunter to open I used holdover in open class for most of one season until I could get a scope that would reliability "click". There are some shooters that continue to use holdover in open class to avoid the dreaded "out of rotation" mistake.

 

[pewpewfever]

Is it possible to simply convert your 16x numbers to those used at higher magnification using a mathematical formula, Or do you have to work it up experimentally?

Also, how does anyone find 40x useful? When I shot benchrest, I could not get a steady sight picture at magnifications that high, and I’d lose the target due to the limited field of view.

 

[shutik]

It is possible to convert, but not practical. You want quick glimpse to reference card, simple is better and yields less errors.

As far as shooting on 40x, it takes practice, but you eventually get good at locating the target quickly.

 

[Motorhead]

If your scope does 32X .... then using your 16X data just HALF the hold over values when at 32x and your golden.

 

[pewpewfever]

My scope has 30, 35, 40, 45, and 50, so I can’t just divide by 2. But if I understand correctly, once I have developed my 16x dope card experimentally, I can make a 40x dope card by multiplying each holdover by 16/40. Is that correct? Would it be more accurate to make a 40x dope card experimentally, and derive the 16x dope card from that?

 

[Motorhead]

Sad fact with most scopes is that they will range differently at differing magnifications. Be it the depth of field and how one perceives Focus to be ideal just gets vaguer as Mag is lower and gets tighter at higher mag.



IDEALLY ... spend the time to get ACTUAL data at both X magnifications and don't trust mathematical conversion as correct because as stated above.



Scott

 

[pewpewfever]

That makes sense. Thanks.

 

[dan_house]

Dont change magnification. You will eventually forget to change it back.



Set the scope to the mag you find works best( Hector MEdina has a great tutorial for doign that on his site ), lock the mag ring/knob and build yer dope sheet for that mag.



one less thing to screw up. 

 

[pewpewfever]

The main reason I would need dope cards for two different magnifications is for Hunter class and open class. But I recognize you are talking about my question whether, in open class, people range at higher magnification and then use a lower magnification to take the shot. Someone told me that keeping both eyes open when sighting at high magnifications helps with finding and staying on target. I will have to try that.