This is about Mig 19 30mm bullet, but in general all other DCS 30mm bullets (like 37mm Mig 15 bullet as well)
I had to fire multiple of these in Mig 19 (hitting the target) to shot it down.
Mirage 2000 pilot commenting Mig-19 bullets:
"How effective were its weapon systems?
“With 30mm canon, just one bullet hitting the target was enough to destroy it. That is if you had computed the gunsight calculations correctly. It had no forward looking radar and no missiles carriage capability. It was the PAF (Pakistan Air Force) which modified it to carry two US made heat-seeking Sidewinder missiles.”