Rifle Scopes calibrating a zoom mildot scope

[jayd4wg]

one of my current scopes is a mildot. I originally got it so that I could begin learning the mildot system and then fatefully installed it on a 22mag - yup...really putting them mildots to good use there. The gun shoots 1" high at 50, DNO at 100, and 5 inches low at 150. beyond that i have a better chance of killing it with a thrown kabar.

One of the most frustrating things about this scope and many like it is that the size of the mils changes with zoom and though the instructions say that it is calibrated for 10x, i question how accurate the markings are on the power ring.

What is the best way to calibrate the mildot system to find that spot where the power ring is as close as possible to the true mildot dimensions and standard?

I'd imagine it would be as easy as placing a 2 or 3 meter target (or yard target if you don't like metric) at a known distance, and making the mils work out, then marking the scope...but how much is good enough?

so a 2 meter target at 500m should be 4 mils...twist until it lines up exactly at 4 mils? (seems big...is my math off?)

Sorry...i was just thinking about this and the coffee has not kicked in yet.

 

[Lindy]

Re: calibrating a zoom mildot scope

Stick up a yardstick, i.e., 36 inches, at 100 yards, carefully measured.

Change the power until 10 mils exactly matches the yardstick, because one mil at 100 yards is 3.6 inches. Viola!

If you want the long answer, read this:

Optically Checking Rifle Scopes

 

[jayd4wg]

Re: calibrating a zoom mildot scope

THANK YOU!! Will be going out to do this this weekend. Wish I had the balls to take the scope apart enough to install a ball detentshrug. Hell, I'd be willing to pin the zoom at 10x on this scope (it's a POS BSA 4-16)

 

[BigBrother]

Re: calibrating a zoom mildot scope

Just out of curiosity, "the size of the mils changes with zoom and though the instructions say that it is calibrated for 10x, i question how accurate the markings are on the power ring."

Yet it's *not* an FFP? How would a scope's reticle change size with zoom and not be an FFP, in which case the problem is moot?

 

[Rafael]

Re: calibrating a zoom mildot scope

He means it changes size relative to the target.

The subtensions in both FFP and SFP reticles change size with power adjustment, but the change is relative to different things.
In an FFP the change is an apparent change to the eye.

 

[jayd4wg]

Re: calibrating a zoom mildot scope

exactly...where as a SFF the reticle does not change size in relation to the scope picture, but the shit downrange looks bigger when zoomed in...so the little dots are BIGGER compared to the target

sorry for the confusing post.