I can confirm both issues.
During my time played I always noticed I had to aim slightly right of the target to get a hit on long distances. It's not the wind or the coriolis effect cause I tried shooting straight south and straight east.

The reloading seems particularly bugged when you're prone or in low fps areas.

Further I noticed that zeroing is bugged / disabled, but that's a separate issue not only for the mosin.

Exactly, switch servers or reloading fixes this. Usually caused by the server being too stressed or overloaded. Mostly happens 1 - 10 minutes after server reset.

I've had the same issue with 5 seperate magnums I found, haven't checked the status of the ammo, so will have to see about that as well

Btw the M4 and the Mosin can fire with ruined ammo, so would be weird if the magnum can't

Epinefrine (Adrenaline) isn't used against shock, it's to reanimate someone
(Unfortunately that doesn't work atm so there is a bug with the epi pen, but differently from what you wrote.)

(Note: I'm not sure how you Americans are used to write Epinefrine, Adrenaline or reanimate, so bear with me)

Sidenote: Saline Bag IV can be used to reanimate someone, not sure if that's intended, but there you go

@DeadlyDaDaMan First of all the human eye doesn't see in fps, secondly the human eye can (and clearly) see the difference between 60 and 120 fps, provided the monitor actually supports 120Hz (or more)

As for the issue: I run a 780GTX SLI setup and run at 30 fps near cities and 20 fps in cities. Absolutely awful performance, but I suspect it will be optimized at some point in the future. Fact remains though, it needs to be improved.