Is this even noticeable outside of like some kind of long range sniping?
Generally speaking from a player perspective.. 'bullet go straight until hits object' is not generally immersion breaking or disjointing to gameplay?
Not sure how much CPU cycles you want to invest here into some ultra realistic falloff to your raytrace.
What's the experience when this isn't accounted for?
dude
the CPU impact of external ballistics is negligible compared to pretty much anything else
you don't need a complex function describing the bullet trajectory (and even if you did, modern CPUs can calculate it with close to no effort) - for any type of ammo fired from a barrel of a known length, there's an easily available table listing the drop-off, velocity loss, etc.
e.g. a .45 ACP 230 grain round fired from a standard 5'' barrel, with sights hypothetically zeroed at 50 meters as far zero:
- shoots ~2.5 cm high at 25 meters, losing ~2% of its muzzle velocity (~4% energy)
- shoots ~11.3 cm low at 75 meters, losing ~6% of its muzzle velocity (~12% energy)
- shoots ~31.8 cm low at 100 meters, losing ~8% of its muzzle velocity (~15% energy)
...
- shoots ~84.6 cm low at 200 meters, losing ~15% velocity (~27% energy)
if you don't think a fall of more than 6" (common rule-of-thumb size of a human head btw) at 100 meters is noticeable even in modern CQC focused shooters, well... consult your ophthalmologist i guess?