I have m856 and have read a lot of threads and all have said some do not ignite. I use h335 as it is the closest to WC-844 military powder that would have been used. I thought that there are two 5.56 tracers 55gr and 64gr and if i read this correctly you have 23.8gr. I think 22-23 gr is used and I used 23 with good results.
What I have read
Advice?
-Use them after wet weather
-using them on steel or hard targets is....interesting
-Use them at long range only (they won't light till about 50-75yds depending on the specific tracer type)
-Use the Army ammunition manual for load data (TM-43-0001-27) to determine seating depth, power charge,etc.
-Win 748, Ball(C)2 and H335 are all good tracer lighting powders in the .223.
-Expect 10%+ to not light.
-Don't expect stellar accuracy. Steadily losing weight from the rear of the bullet while it's flying doesn't do much for accuracy.
As to why he has them, probably because they're fun. They set things on fire. We're all basically here because we like things that go "boom" and break things at a distance. Setting things on fire from a distance is yet another extension of that theme.