Moa. At 500m we are talking 1/4". Not 1/4 moa but 1/4" at 500m. Absolutely inconsequential. While I understand you want to take all the variables out of the equation, this one in particular isn't one to lose sleep over. Pick a number and run with it. Due to all the bases and rings available you need to measure your rifle and you're rifle only.
That' said my .243 axis with a 40mm objective hunkered down close to the barrel is 1.6", and my .300wm with a 50mm is 1.8".
Just pick a number and go but 1.6" does sound quite likely.
This data is entry is the least of your concernes. .1moa means nothing for your purpose. It doesn't even factor in. It's a number that is rounded out in any calculation you would be making.
With your setup your week points are going to be elevation, temperature, humidity, and barometric pressure. Those elements will make those turret numbers little more than approximations and that .1moa is just as likely to help you as it is to hurt you.