GSW "first responder" guidance

As an instructor, I thought it prudent to get some first responder training. I am taking a First Medical Responder course. GSW was not covered to my satisfaction in spite of the fact that all my classmates are LEOs.

I have also read the material from the TCCC (Tactical Combat Casualty Care) curriculum.

One example that stands out is the difference in recommended use of a tourniquet. Wartime has always been the initiator of dramatic changes in technologies and protocol especially with respect to first responder care.

What should a firearms instructor know and what is best first responder practice in tending to a GSW. Is there a good commercial kit that anyone would recommend for me to carry?

Thanks in advance for your help.