While there are a wide variety of self defense handgun rounds for your common 9mm’s, .40 S&W’s, and .45 ACP’s, the market of defensive designed 5.56 rounds is a much smaller field.
Conventional 5.56/.223 commercial options like the M193 (55gr lead core), M855 62gr mild steel core, and 62gr lead core all perform to certain standards based on their designs. These designs are for longer distances.
These rounds are designed for 16-20″ barrels of the conventional 5.56 rifles and carbines.
With the increased popularity and use of AR “pistols” as defensive carbines with shorter barrels a round that performs well at defensive distances out of those shorter barrels is highly desirable.
Sage Dynamics took out Hornady’s 75gr SBR HD, a round advertised as being exceptional in shorter barrels for self defense.
It’s a longer video but there is a tremendous amount of information about the 75gr round and ammunition performance in general. Since I personally just picked these up for use in my home defense rifle I’m glad to see Sage Dynamics putting in effort to give people solid information.