“I like the ‘tracer’ lines scratched into the film in post-production to show the path of the bullets fired.”........
Do the bullet manufacturers make tracer rounds today for hand gun weapons?
Yes, they still do make tracer. An AmmoSeek search for .45 ACP tracer shows four sources:
https://ammoseek.com/ammo/45acp?ikw=tracer
A search for the more popular 9mm shows five: