I'm looking at picking up a Nikon M series and I downloaded the spot on app to see if I liked it.

My question is in the app you plug all that data in and it gives you your ranges for the bullet drops. For example 100 yard zero and 500 to target with magnification at 4x it may start off with 100,401,684,898,1106 and so on. But with magnification at 16x it will be like 100,197,307,407,520 and so on. Why do the ranges change when magnification changes.

it also says set sights to shoot -57.4 inches low at 500 for 100 yard zero

Keep in mind I don't know much about long distance shooting.

Am I so dumb that nobody wants to answer or does my question not make any sense ?

OP,  valid questions but there might not be a lot of folks on the HTF with experience with that particular scope.  You might get more results posting in the Optics forum.

Sorry... I see that you have already posted on the optic forum.

It is a second focal plane scope so the reticle measures differently at each magnification vs a first focal plane where the reticle is the same through the entire magnification range.

Do a little research on first focal plane vs second focal plane.  There is tons of info on it that will explain it better than I can.

The biggest problem with Nikons scopes is they have always had limited internal adjustment. Generally 30-50 MOA  with the higher mag scopes having less adjustment.

The glass quality and warranty is a good bang for the buck and SFP vs FFP is just something you can learn. A decade or so ago there were hardly any FFP scopes and people were still ranging and making exceptional shots.

FYI I had a 10-12 year old monarch UCC that somehow developed a small filament in the outer edge of the sight picture. I used it quite a bit and never had another issue. I sent it to nikon with no proof of purchase and they replaced it with a new 5-20.

Foreman, Think about a camera lens, you zoom in to make the target appear closer to you. Same works for the Nikon rifle scope's you are looking at.
Nikon's M-Series are built with MONARCH glass and their special lens coating's on all glass surfaces. I have been doing some freelance PR/Shooting Event's for Nikon for almost 5 years now. I had the plaesure of doing some product testing when they first came out and I was impressed. I think I have purchased, yes, I had to buy them, almost all of the M-Series scopes with the 3-12 and 1-4 being my favorites for my 5.56's and the 2-8 on my light weight coyote rigs. The P-Series 3X Carbine scope is also one of my favorites and one my son uses for competition's.
As for the internal adjustment's being limited, may be true compared to more expensive scopes but you will still have plenty of adjustment to shoot to 700-800 yards. Heck, I have only done that a dozen times in the last 5 years and I have a range where I can shoot 1000 yards 90 min. from me.
I truly don;t think you can go wrong picking one of Nikon's M-223 scopes. Great glass, crisp and clear, tough and a great No Fault Warranty. Not to mention a great price.

Here's a screen shot showing what you asked about. Again, think about  the zooming in and closing the distance,also the second focal plane makes the target appear larger to you.

I know about sfp scopes and how most are calibrated for use at 10 x. I guess I never thought about how much everything changes when you zoom in and out.

Many are set for 10x, but NOT ALL!  They may be marked on the magnify ring, or in the manual, but they are not all set for 10X.