From AR15.com
Trijicon numbers SKU: TA31-D-100581 and TA31-D-100582 (same but with LaRue mount) The "Horseshoe" represents a 19 inch target at 200m.
The open section is a 19" target at 300m.
the 4 and 5 lines also represent the same. Past that, it is the gap that represents the 19" at the respective distances.
Now this reticle was designed for both the 14.5 inch M249 and the 19.5 inch M249 barrels.
So the short (lower) BDC lines are for the shorter barrel (say if you are using a M4), and the longer lines work with the longer barrel. For M4 and M16A4 rifles.
Trijicon numbers SKU: TA31-D-100581 and TA31-D-100582 (same but with LaRue mount) The "Horseshoe" represents a 19 inch target at 200m.
The open section is a 19" target at 300m.
the 4 and 5 lines also represent the same. Past that, it is the gap that represents the 19" at the respective distances.
Now this reticle was designed for both the 14.5 inch M249 and the 19.5 inch M249 barrels.
So the short (lower) BDC lines are for the shorter barrel (say if you are using a M4), and the longer lines work with the longer barrel. For M4 and M16A4 rifles.