Access to space has historically been limited to a handful of countries due to the overwhelming costs associated with space flight. While the average cost per kg to low Earth orbit has decreased substantially, this cost is still too high to enable more open access to space and ultimately interplanetary travel. Obtaining the highest performance from oxidizer systems is critical to enabling cost-effective and reliable launch vehicle operation. Stainless steel material is attractive because of its relatively high strength-to-cost ratio. Unfortunately, stainless steel is flammable at oxygen pressures over 7.7 barA (110 psia), and so safe operation requires specific testing of ignition mechanism. Particle impact is a common ignition mechanism in flowing gaseous oxygen (GOX) systems that use stainless steel. The literature suggests that characteristic elements needed for particle impact ignition are (1) particles that can be entrained in the flowing oxygen, (2) high gas velocities, typically greater than ∼30 m/s, and (3) an impact point ranging from 45° to perpendicular to the path of the particle. This paper describes particle impact ignition testing of 304L stainless steel targets using 316L particulate in ∼700 K GOX at supersonic velocities and pressure up to ∼100 barA (1,450 psia). We put special emphasis on the impact point and the influence of the oxidizer flow impingement angle on the likelihood of ignition. Published guidance describes an impact point ranging from 45° to perpendicular to the path of the particle; this paper questions that guidance and shows it to be nonconservative. We suggest new data-driven safety-centric guidance using 20° instead of 45° for enhanced safety and reliability of oxygen systems.