A patch or two back, tank rounds stopped rendering well before they used to. This makes it much more difficult to gauge long range shots, especially for high drop projectiles. Please revert it to the way it was, or add a few 100m to the render.
It must be one of your personal settings. The way I am set up, I can watch a tank shell fly over the full course of its short life.
Projectile rendering at long range (>300m) never worked properly for me. When im driving a vehicle/aircraft, i often get hit by invisible projectiles. I dont see trails or explosions either. I loose health in big chunks, but cant see where the fire is coming from. Its super annoying. Im very conservative with spawning vehicles because of this.