Depends.
If I'm hiding, never.
If I'm in a visible (and ALWAYS breakable) spot, depends on the # of zombies, the # of teammates with me, and the health % of said zombies.
Overall, I would say I run out of ROUNDS (technically speaking, a bullet is just the projectile, not including the propellant) about 20% of the time.
That is 20% in the current config. Now to that add zombie respawn at full health... and increase that % by about 200%.
would it be possible to have one week without parachutes and zspawn?
as a trail to compare the game play players would experience.