Sighting in from a roof top mock up at the range. As the sun continued to set we could watch the sun reflect off the .300 WinMag bullets as they arced along their trajectory with the naked eye. It looked like watching a tracer round but was just the setting sun reflecting off the copper jacket of the round.
Sniper/spotter at a unknown distance range. Note the Viper laser range finder in the foreground, a very useful piece of kit with a variety of functions beyond range finding.
Reflexive Fire 
I still remember how amazed I was being able to track the trajectory of bullets with my naked eyes when I first witnessed tracers in use. I was struck by how crude a weapon a firearm truly is. Ultimately inspired that one line I used about puncturing vital organs. 😉
The more I learned about guns the more fascinated I became with how they function mechanically. Some designs are really brilliant but you are right in that guns have changed very, very little over the last hundred years. I think that many reasons exist for this, including job security and USG contracts, but I think we should at least be using caseless ammunition by this point if not full blown rail guns in a M4 size package.
I believe caseless ammo has been feasible for a couple decades, now. I suspect you’re right.
5.8 caseless has been around since the late ’80s…so, yeah, I suspect cultural/economic concerns are holding down the progress of firearms much more then any lack of technology. I suppose it is a double edged sword, do we really want more deadly weapons when our enemies will have them as well, 5-10 years later.