SFP hash mark ratios

[bojangles]

So, I have this sfp vortex scope, it’s a strike eagle, 3x18,  and I’ve recently learned that the hold over marks (don’t know what they are called?) change size with magnification adjustments.  And, that they are only true to proportion on the highest magnification setting.   
So, what is the ratio I can expect when I dial the magnification back?  I’ve been told that the 1 moa lines become 2 moa at 9 power.  So, I’d like to know ratios at 3,6,9,12,and 15 power so I can make quick holdover decisions in the field.

so, I wound up killing an elk last fall with this rifle, not knowing this information.  I backed off the scope a little bit, used hash marks, but I hit the elk about a foot high at 478 yards.  I was sighted in at 200.  But the elk dropped in his tracks, with the high  shoulder hit.  
Can anyone confirm this, and what might the true ratios be ant different magnification setting?

 

[JSR]

It should be in the manual for your scope. If you dont have it, its probably on the vortex website. 

[NMBPMAN]

In SFP scopes the reticle is only supposed to be true to measurement when the scope is on its highest magnification setting.  FFP scopes change the size of the reticle when you change the magnification so the measurements are the same no matter what the scope is set on. As far as what the ratio turns into at different magnification settings you’ll more than likely have to spend some time at the range figuring that out unless someone on here or the internet has already done all that. 

[Crazymonkey]

I didn't  see anything  in there manual  that gives you the data on hold over .But most are only true at full power unless  they are noted for a set magnification. Some are just short of full power and will usually  have a mark or dot on the mag ring.First focal plain is the way to go if you can get use to the cross hair  shrinking and growing  with magnification. 

[MMACFIVE]

Don’t make this too difficult. 
 

Let’s assume your max magnification is 20x. If your marks are 1 moa at 20 then they are 2 moa at 10x (1/2 the max magnification) and 4  moa at 5x…

When you half the magnification you double the hash marks. 
 

Good luck 

 

[bojangles]

2 hours ago, MMACFIVE said:

Don’t make this too difficult. 
 

Let’s assume your max magnification is 20x. If your marks are 1 moa at 20 then they are 2 moa at 10x (1/2 the max magnification) and 4  moa at 5x…

When you half the magnification you double the hash marks. 
 

Good luck 

 

That’s what i thought…thanks for the input.

[MMACFIVE]

2 hours ago, bojangles said:

That’s what i thought…thanks for the input.

Just to be clear I’m talking about SFP scopes which the Strike Eagle is.
 

Hash marks not changing is one of the advantage Mac that First Focal Plane have.