I just recently put a new IFAK together. Here's n'y list:
2 vented chest seals
1 Israeli
1 set of decomp needles
1 4" rolled gauze
1 Mylar blanket
1 CAT gen3
1 hemostatic gauze
1 set of shears
1 red sharpie
2 chem lights (1 red, 1 white)
2 pairs of nitrile gloves
1 roll of paper tape
1 nasopharyngeal (packed with a little tube of lube)
I would like to carry a SWAT TQ with that (as an option as TQ or pressure dressing), but I'm out of room.

I am part of a tight knit group of friends who happen to enjoy firearms and related things. We have a combat medic as well as an NP who specialized in trauma care, and who rode on an EMT truck in BAD neighborhoods for years. Every now and then, they set up a class for the rest of us, so we all get a little more advanced knowledge. I gotta say, if you think that you had enough training after 8 hours, you're dead nuts wrong.
And keep in mind, there's more to life than penetrating trauma/GSWs. There's injuries to the eyes, the bones, burns, toxic stuff, and the list goes on. Even basic CPR is often overlooked because some people can't fathom any injuries that aren't shot related.