How accurate is range finding using the TMR Reticals on a Leuopld Mk IV?
What power setting does it need to be set on? I know this will affect the equation, or does it?
It's as accurate as your estimates. If you perfectly estimate the size of the target and the mil reading, you'll get a perfect range. If you estimate the target as 1.1 mil and it's 1.2, or the target is 32" instead of 36", your range will be off. Generally, it's alright out to ~500 yards. After that, find a different method (i.e. laser).
What power setting does it need to be set on? I know this will affect the equation, or does it?
