Everyone is different. Here’s how you do it. Go down to Toys R US and buy a jug of Playdoh. Roll two Playdoh balls and place them on the rail where you would mount your scope. Place your scope on the two Playdoh balls and push the scope down until you get a comfortable cheek weld. Remove the scope and measure the height of the Playdoh balls where the scope made the indentation. This will give you a great idea on what height rings you’ll need
That’s pretty genius.