Thanks for reply. I have never been on the recieving end of a gun, but found this info:
"For those on the receiving end of tracer ammunition, there is a well-known optical illusion whereby the tracer rounds appear to be traveling slowly, but as they get closer, they appear to speed up considerably."
"A recent patent U.S. Patent Application 20040099173 covers the use of an LED and capacitor, instead of a pyrotechnic compound, in an attempt to stop the tracer being seen from the front."
Its from Wikipedia though