Could someone explain what all the stuff is on the reticle? What do the 5 / 10 / 15 marks below the center relate to? I assume its some sort of range finding reticle. What does the "3" and circle to the left and below of the center do?

http://216.73.104.119/tmp/CQB.jpg

http://ar15.com/forums/topic.html?b=3&f=18&t=256400

ealier thread that will help you out.....

Those are mils

The 3 and circle is a rangefinder.  If a bad guys head [or corresponding sized target like height of a crow from tail to shoulders or prairie dog] fills the circle at 3 it's 300meters to the guy or dog crow or whatever.  

smaller circles are probably 4 5 and 600 meters from left to right.  That's all at 4 power including mils as the reticle is constant sized.  

If you know the range and how many mils to compensate for drop the mils are right there for you.  If not I was thinking just shoot and use the scale to work holds based off where bullets drop.  

The donut I imagine is just for speed of picking up the reticle.  Perhaps at close range it could do something for you like give you an idea of the beaten zone of a burst or maybe give a visualization of a pattern with a shotgun corresponding to a range or something like that.    I don't really like the donut.  I would rather it be not as thick or maybe not exist at all and just have a larger center dot.

Pretty well devised though as most reticles of this type I just really hate and I didn't mind this one.  

I think it would be nice to see the little circles placed at their corresponding BDC for 5.56 62 or 77 grain and just use them as aiming points. That would be faster.  Better yet put an 18inch scaled stadia through the center of the circle for ranging shoulders if availible or just the guy's head if it's all he's presenting-- maybe drop a line and connect at least the 300 and 400m dots like a shepherd reticle creating a bunch of little crosshairs.  Of course that would probably limit the circulation and sales of this optic as it is probably used on everything from shotguns and M4's to 7.62 rifles for all I know.  Maybe an optional reticle would be in order but I wouldn't expect anything of the sort from a major optics company.  

The CQB is a close quarters and rangefinding reticle.  Edge-to-edge inside the donut = 10" (human head) at 100m.  Center (1MOA) dot to inside donut edge is headsize at 200m.  The other circles are headsize at 300, 400, 500, 600m respectively.  The donut exterior edge-to-edge is 18MOA (slightly smallish human shoulders at 100m).  The horizonal stadia are measuring mils if you want to use that system for rangeing.

The reason this reticle doesn't have BDC markings, but rather rangefinding markings, is because most of the scopes IOR puts it on have BDC cam turrets.  For example, if your target is 10" and fits inside the leftmost circle, then it is at 300m, so you just twist the BDC turret to "3" and the reticle is deadon, no holdover/under necessary.