Originally Posted by kalnaren
An RS MG belt has them every 12-14 rounds, IIRC... though that may have just been in aircraft.
Also, white BB's are a bitch in winter. You can't see where nothing is going!
These days it's actually 1 in 4 that is a tracer, maybe 1 in 5, but for most usage, it's every fourth round is a tracer.