Trijicon TA31F ACOG

[JGarcia]

We've been doing some figuring and studying on the TA31F ACOG here at the school. Supposedly the reticle is for an M4 firing M855 ammunition, but the numbers don't exactly add up.

Out of curiousity does anyone know if Trijicon uses a 6400 miliradian circle or the mathematically correct 6283.2 miliradian circle?

I've been doing some figuring on my own tonight and the red chevron which is supposed to equal an E Type at 300 M doesnt quite add up, using either 6400 Mils or 6283.2 Mils, but 6400 is about 5 Meters closer than the mathematically correct 6283.2.

I worked it out like so,,,,

19.5" wide E type X 25.4= my constant of 495.3 divided that by the mils I got from converting their MOA data for that reticle from MOA to mils, using both 6400 and 6283.2.

Using 6400 mils I get 304 M.
Using 6293.2 mils I get 309.6 M.

The width of bottom of the red chevron, should equal 19.5" or 300 M.

So, let me go back and see if I can find any errors, in my assumptions. Maybe they used a number other than 19.5" wide for the E type.

It also looks like the figured the BDC with a 20" barrel, even though the reticle is supposedly for an M4. Wont make a difference for most, but just thought you might like to know; zero accordingly.