M-196
red tip can be used in anything...
M-856
orange tip is supposed to require a 1x7 to keep stable...
though the bullet is identical in length and bearing surface as a M-855 green tip ( I have both sitting on shelf side by side), and we know the green tips are fine in a 1x9... I have not fired M-856 out of my 11.5" 1x9 barrel yet....
Problem with tracer is that with 556 ammo fly at high speed, by the time your eye picks up the trace at within 100yd, the bullet is hitting the dirt if you indeed shooting 100yd range. Sooooo, we need a bit more flight time/distance for the eye to pick-up the trace.
I have shot M-196 out of a 7.5" barrel, this brings velocity down to the 2200 fps range, and I can pick up the trace at approx 50-75yd, and watch them burn into the dirt.
EDIT----> based on dangerdan' #s given, I have found that I have posted "BUM" info...
the tracer has no paint on the tip, and is indeed same length as the green tip, so I weighed it.... it is 54gr, making it a M-196.... I know I have an orange floating loose, just cannot find it... but dan' numbers is correct.