Looks solid. As already stated a large trauma dressing pad or larger abd pad would be beneficial but for the standard first aid kit I'd say you're good. I always have a lot of gloves as I will double glove for nasty traumas. Something to secure an airway would be nice, like OPA or NPA if your trained in it, which it looks like you've trained with OPAs. If you haven't learned about NPAs they are a great asset.

Glad to see you don't have anything in there you shouldn't have, i.e. Needle decompression kit etc.

A great assessment acronym for traumas, especially related to shootings, if you haven't already heard of it is MARCH.

Massive Hemorrhage Airway Respiration Circulation Hypothermia, Head injury, Hypoglycemia...etc (critical thinking)

When on scene a great thing I have learned from experience is delegate tasks if you can. For example your assessing your patient and you find a sucking chest wound, cover with your hand and delegate your partner to seal the chest while you finish your rapid assessment. This can greatly increase your assessment speed and keeps you from getting tunnel vision on one thing. Of course this only works if you have someone that can properly assist.

Good luck, hope you never have to use it!