Re: what power for proper ranging?
You can range at any power is true. The scope is setup to range at max power per the instructions they give you.
If you range at 5x instead of 22x you need to do the following.
Get the MOA or MIL reading as you normally would, and calculate the range exactly how you normally would.
Now that you have a number, let's say it comes out to 425 yards
You take the range and multiply by 22/5.
This is your max power divided by the power you ranged at. That means that the true range is (22/5)*425 = 4.4*425 = 1870 yards
Let's look at it from the "how'd you do that?"
The reticle on a second focal plane scope never changes size. Therefore, the dots change true spacing as the magnification changes.
If you have an object that's 1 MOA across at 1000y it's real life size is about 10.5"
If you look at it on 22x, the object looks to be 1 MOA, but if you look at it on 5x, it appears to only be about 0.227 MOA
You're working from a pure ratio of the magnification now. Calibrated power ( generally Max power) is always the numerator, in this case, 22 power.
The power you're ranging at is always the denominator, this case it's 5x.
Just as a sanity check, verify that if you take the calibrated power (22) and divided it by max power (22) you get 1
22/22 = 1, therefore if you range at max power you have no further changes to make.
Does that make sense or did I just stir the mud puddle?
