any Miliradian FFP scope or SFP MRAD set to its 1:1 magnification is an analog range finder.
Height of target in inches ÷ 36 x 1000 ÷ Mil reading= range in Yards
with MOA reticle it's
target size in inches x 95.5 ÷ MOA reading= range in yards
Back around 15 years ago, for me in Hunter FT, when I used to use a scope at the required 12x or less, I tried ranging with the reticle in Mil and FFP. I was even down prone back then using attached bipod with the butt of the gun resting on my hand left arm somewhat steady. My scope reticle was .5 mil and it was still fairly difficult to bracket precise enough to get reliable distance estimations based off KZ sizes which I knew.
For example a 1.5" KZ that measures .8 mil is at 52Y and measured at .9 mil is at 46Y. It's enough to miss if one doesn't guess the wind nearly perfectly because we are shooting at circle shaped KZ's. That's only 1 click's difference to make out in the reticle. Really it was more having the gun steady enough to see the exact difference. Then as the KZ's get smaller like 1.25" at those same distances it gets even harder to hit them.
I also tried this with a H59 mil reticle in all .2's. It was a little easier than using the .5 mil reticle but measuring say .85 mil vs .8 or .9 is getting hard to see to be effective. Again it's hard to hold the gun still enough, at least for me it was.
Later my eyes started fluctuating with I can only guess as due to blood suger levels, or who knows what combination of other eye problems?? because I kept having to change the scopes diopter setting to keep the reticle focused which affects consistent ranging using the focus of the scope. After 2-3 tries over the years using different scopes I said the heck with it and started using a LRF/ laser range finder all the time in Freestyle/unlimited.
I shoot just for the fun of it now, actually not competing with anyone most of the time, and enjoy the matches as much as ever.
Aside from the above, and for the record, we have a bunch of shooters in our club that are capable of winning any FT match anywhere and we don't see a major difference in scores from Unlimited, Hunter, or Open. It's basically who was shooting better on that particular day and who made the least mental mistakes.
The exception though is probably in WFTF on only "WINDY" days when their scores are lower but if the wind is low they do just as well as we do if not winning the match.
But I have to applaud our club member Kent who shot a 48/48 in Hunter Saturday on a fairly tough course facing three directions in IIWTG 12-20 mph winds!! I shot a 45 in Unlimited and another guy in Hunter also got 45 then behind him was a 44, and the other better scores weren't much lower. IIRC high WFTF was 37. Windy enough coming from 10 oclock on lane 8 that I had to aim out 6 MOA to hit the 1 7/8th KZ both times at 55Y and not much less at the 48Y to hit the 1.5" KZ twice. Ha and I thought I was doing well???!!!!
As I keep mentioning it doesn't matter at this point if a LRF is used or not as far as scores go with the almost 20 fpe rigs.