Zeroing at 100m. .5cm off centre.

[T65]

Hi Guys
Using a mil scope with 0.1 mil adjustments.
If you try to zero at 100m's and your rounds group .5cm off centre. How do you true for dead centre as 1 click will take you .5cm in the opposite direction. Not much of a problem at that distance but at 500m it will be 2.5 cm off if I am doing my calculations correctly. Which will probably affect any ballistic calculator.
Does this indicate something wrong somewhere? Or is it the limitation of the coarser mil system?
3 round groupings where 0.234 and .287 MOA

[markymark]

Most ballistic calculators have zero offset function. So you just tell the app or program you are offset by x or y left / right / up / down and it will factor into calculations. 
 

strelok for example:

 

[Catch-22]

Correct. I also use the same setting for when I zero with and without a moddy on as it allows for change in poi.

[T65]

Thanks didn't think to use it for that. 🙄

[Charlts]

I’m not good enough to notice the difference, I’d rather it was slightly high and if needed round down my corrections further out.

[Catch-22]

A side note, the zero offset is also really useful when you have multiple barrels/calibre’s you spin on and off.
Zero the scope for one barrel, spin the other barrel(s) on and note the different scope value. Enter this offset into your Kestrel (or other ballistic solver) and you never need to remember the scope settings between each barrel when dialling your shot.