Standard tracer ammo, yes. As was the case with most weapon systems in WWI, innovation ran rampant and the various armed forces tried out any number of solution

Standard tracer ammo, yes. As was the case with most weapon systems in WWI, innovation ran rampant and the various armed forces tried out any number of solutions such as explosive-filled bullets[1] [1]https://en.wikipedia.org/wiki/Pomeroy_bullet https://en.wikipedia.org/wiki/Pomeroy_bullet