• a Basic Emitter to emit the initial shot
• a Condition based on Age of the particles shot with Inside Range (Lower: 50F, Upper: 90F)
• a Reproduce Emitter parented to the Condition so when a particle hits that condition it spawns.

All was working fine until I noticed there were many particles that were not triggering the condition. Why would that be happening?

I made another condition to increase the radius after 90F Lifetime to see how many weren't adhering to the condition:

It seems like when I reduce the Reproduce Emitter from 60 down to 10, all works fine - they all explode.
The settings I had on the Reproduce Emitter:
Count: 60 (or higher)
Per Particle
Count Variance: 5
Kill Source: on
Continuous: off